Dermatopathology: Diagnosis by First Impression, 2nd Edition

Dermatopathology Diagnosis by First Impression Dermatopathology: Diagnosis by First Impression, 2nd edition. Christine...

Author: Christine J. Ko | Ronald J. Barr

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Dermatopathology Diagnosis by First Impression

Dermatopathology: Diagnosis by First Impression, 2nd edition. Christine J. Ko and Ronald J. Barr. © 2011 John Wiley and Sons, Ltd. ISBN: 978-0-470-65711-9

To Ulla, Anna, Jessica, and Sara, who let me pursue my career while they took care of everything else. (RJB) To Peter. (CJK)

Dermatopathology Diagnosis by First Impression 2nd edition

Christine J. Ko Associate Professor of Dermatology and Pathology Yale University School of Medicine New Haven Connecticut USA

Ronald J. Barr Dermatopathologist Laguna Pathology Medical Group Laguna Beach California; Professor Emeritus Dermatology and Pathology University of California Irvine California USA

A John Wiley & Sons, Ltd., Publication

This edition first published 2011 © 2008 by Christine J. Ko and Ronald J. Barr, 2011 John Wiley & Sons, Ltd. Wiley-Blackwell is an imprint of John Wiley & Sons, formed by the merger of Wiley’s global Scientific, Technical and Medical business with Blackwell Publishing. Registered office:

John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK

Editorial offices:

9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 111 River Street, Hoboken, NJ 07030-5774, USA

For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell The right of the author to be identified as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. The contents of this work are intended to further general scientific research, understanding, and discussion only and are not intended and should not be relied upon as recommending or promoting a specific method, diagnosis, or treatment by physicians for any particular patient. The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of fitness for a particular purpose. In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of medicines, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each medicine, equipment, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions. Readers should consult with a specialist where appropriate. The fact that an organization or Website is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Website may provide or recommendations it may make. Further, readers should be aware that Internet Websites listed in this work may have changed or disappeared between when this work was written and when it is read. No warranty may be created or extended by any promotional statements for this work. Neither the publisher nor the author shall be liable for any damages arising herefrom. Library of Congress Cataloging-in-Publication Data Ko, Christine J. Dermatopathology : diagnosis by first impression / Christine J. Ko, Ronald J. Barr.—2nd ed. p. cm. Includes bibliographical references and index. ISBN 978-0-470-65711-9 (pbk. : alk. paper) 1. Skin–Diseases–Diagnosis–Atlases. 2. Skin–Pathophysiology–Atlases. I. Barr, Ronald J. II. Title. RL96.K6 2011 616.5′075—dc22 2010047245 A catalogue record for this book is available from the British Library. This book is published in the following electronic formats: ePDF 9781444340211; Wiley Online Library 9781444340235; ePub 9781444340228 Set in Frutiger Light 9/12 pt by Toppan Best-set Premedia Limited

01

2011

v

Contents

Preface, vii

Interface reaction, 141

Acknowledgments, ix

Granular “material” in cells, 148 “Busy” dermis, 153

Chapter 1 Shape on Low Power, 1

Dermal material, 156

Polypoid, 3

Change in the fat, 168

Square/rectangular, 8 Regular acanthosis, 14

Chapter 3 Cell Type, 179

Pseudoepitheliomatous hyperplasia above abscesses, 18

Clear, 181

Proliferation downward from epidermis, 22

Melanocytic, 196

Central pore, 32

Spindle, 206

Palisading reactions, 36

Giant, 218

Space with a lining, 41 Epidermal perforation, 52

Chapter 4 Color—Blue, 227

Cords and tubules, 55

Blue tumor, 229

Papillated dermal tumor, 61

Blue infiltrate, 238

(Suggestion of) vessels, 68

Mucin and glands or ducts, 246

Circular dermal islands, 80

Mucin, 250

Chapter 2 Top-Down, 85

Chapter 5 Color—Pink, 257

Hyperkeratosis/parakeratosis, 87

Pink material, 259

Upper epidermal change, 98

Pink dermis with vessels, 265

Acantholysis, 108

Epidermal necrosis, 268

Eosinophilic spongiosis, 118 Subepidermal space/cleft, 124

Index by Pattern, 275

Perivascular infiltrate, 131

Index by Histological Category, 280

Band-like upper dermal infiltrate, 136

Alphabetical Index, 283

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vii

Preface

The purpose of this book is to focus on a selection of commonly tested entities, showing low- to high-power views. Major differences among diagnoses that are sometimes confused are emphasized on “Key differences” pages to help train the eye to rapidly notice distinctive features. As a picture is worth a thousand words, text is kept to a minimum. This book is not meant to replace major textbooks of dermatopathology. Ultimately, the book should be used as a companion to dermatopathology textbooks and as a pictorial reference/study

tool, given that this approach is utilized by the experienced dermatopathologist when constructing examination questions. Often, the major distracters are based on gestalt rather than etiology or conventional classifications. It is often the look-alikes that are the most deceptive even though they have no obvious relationship to the correct diagnosis. This book will also be helpful to the dermatopathology novice as it introduces a simple and effective way to approach a slide, and common diagnoses have been specifically included.


ix

Acknowledgments

Dr. James H. Graham, MD, master of dermatopathology and dermatology, who taught me most of what I know. (RJB)

Cowper, Dr. Antonio Subtil, Dr. Anjela Galan, and Dr. Marcus Bosenberg), Dr. Jean Bolognia, and always my family. (CJK)

Dr. Ronald Barr, my dermatopathology colleagues at Yale (Dr. Jennifer McNiff, Dr. Earl Glusac, Dr. Rossitza Lazova, Dr. Shawn

The authors also thank Martin Sugden, Rebecca Huxley, and Lindsey Williams for their assistance in the publication process.


1

Shape on Low Power • Polypoid, 3 • Square/rectangular, 8 • Regular acanthosis, 14 • Pseudoepitheliomatous hyperplasia above abscesses, 18 • Proliferation downward from epidermis, 22 • Central pore, 32 • Palisading reactions, 36 • Space with a lining, 41 • Epidermal perforation, 52 • Cords and tubules, 55 • Papillated dermal tumor, 61 • (Suggestion of) vessels, 68 • Circular dermal islands, 80


Shape on Low Power

Polypoid

3

• Polypoid shape • Acral skin [thick stratum corneum with stratum lucidum (long arrow)] • Dermal nerve bundles (short arrows)

1

Accessory digit

4

Shape on Low Power

Polypoid

• Polypoid shape • May see a slight invagination of the surface epidermis with underlying sebaceous glands • Surface epidermis often slightly acanthotic and hyperpigmented

2

Accessory nipple

• May see mammary ducts or apocrine glands deep • Dermis with numerous smooth muscle bundles (arrows)

Shape on Low Power

• • • •

3

Polypoid shape Thin epidermis Vellus hairs (arrows) Cartilage not always present

Polypoid

5

• Differential diagnosis of numerous vellus hairs – Eyelid/earlobe/sometimes facial skin – Vellus hair nevus

Accessory tragus

6

Shape on Low Power

Polypoid

• Polypoid shape • Acral skin • Fibrovascular stroma [thick collagen (arrows)]

4

Digital fibrokeratoma

Shape on Low Power

(a)

(b)

(c)

(d)

Polypoid shape a Accessory digit: nerve bundles in the dermis b Accessory nipple: sebaceous glands, mammary ducts or apocrine glands, smooth muscle bundles in the dermis

5

Polypoid

7

c Accessory tragus: vellus hairs in the dermis d Digital fibrokeratoma: collagen in the dermis Note Other entities may also be polypoid, e.g., intradermal nevus; see page 151

Key differences

8

• • • •

6

Shape on Low Power

Square/rectangular

Square/rectangular shape Thick, pink smudgy collagen in dermis Plasma cells around vessels Atrophic or absent adnexal structures

Morphea

Shape on Low Power

Square/rectangular

9

• Square/rectangular shape • Altered, reddened collagen (necrobiosis) layered with inflammation • Giant cells and plasma cells are prominent

7

Necrobiosis lipoidica

10

Shape on Low Power

Square/rectangular

• Square/rectangular shape • Normal-appearing collagen bundles in dermis • No increased mucin

8

Normal back skin

Shape on Low Power

Square/rectangular

11

• Square/rectangular shape • Slight widening of space between collagen because of mucin (arrow) • No increase in fibroblasts

9

Scleredema

12

Shape on Low Power

Square/rectangular

• Square/rectangular shape • Slight widening of space between collagen because of mucin (long arrow) • Increased fibroblasts (short arrows)

10 Scleromyxedema

Note Lichen myxedematosus is histologically similar but clinically different Note Nephrogenic systemic fibrosis may show similar findings

Shape on Low Power

(a)

(b)

(c)

(d)

Square/rectangular

13

(e)

Square/rectangular shape a Morphea: thickened bundles of collagen with loss of fenestrations between collagen bundles b Necrobiosis lipoidica: reddened collagen sandwiched between layers of inflammatory cells (giant cells, plasma cells)

11

c Normal back: normal-sized collagen bundles, no increased mucin d Scleredema: mucin between collagen e Scleromyxedema: mucin and increased fibroblasts

Key differences

14

Shape on Low Power

Regular acanthosis

• Epidermal acanthosis • Parakeratosis • Full-thickness disorder of keratinocytes with atypical cells (short arrows) and mitoses • Basal layer may appear normal (“eyeliner” sign) (long arrow)

12 Bowen disease

Shape on Low Power

Regular acanthosis

15

• Epidermal acanthosis • Clear cells well-demarcated from the normal epidermis and adnexal keratinocytes

13

Clear cell acanthoma

16

• • • • • •

Shape on Low Power

Regular acanthosis

Epidermal acanthosis Parakeratosis Neutrophils in stratum corneum (asterisk) Hypogranulosis Thinned suprapapillary plates (long arrow) Dilated vessels in papillary dermis (short arrows)

14 Psoriasis

Shape on Low Power

(a)

Regular acanthosis

17

(b)

(c)

Regular epidermal acanthosis a Bowen disease: disordered keratinocytes and atypical mitoses b Clear cell acanthoma: pale/clear keratinocytes well demarcated from normal epidermis

15

c Psoriasis: confluent parakeratosis above thickened epidermis, neutrophils in stratum corneum, normal keratinocytes, thin suprapapillary plates, dilated vessels

Key differences

18

Shape on Low Power

Pseudoepitheliomatous hyperplasia above abscesses

• Pseudoepitheliomatous hyperplasia above abscesses • Yeast forms (arrow) that classically show broad-based budding

16 Blastomycosis

Shape on Low Power


19

• Pseudoepitheliomatous hyperplasia above abscesses • Brown-colored, septate, rounded, “hot cross buns” (Medlar bodies, sclerotic bodies, copper pennies) (arrow)

17

Chromomycosis

20

Shape on Low Power


• Pseudoepitheliomatous hyperplasia above abscesses • Large (∼80–200 μm) spherules containing endospores (arrows)

18 Coccidioidomycosis

Shape on Low Power

(a)


21

(b)

(c)

Pseudoepitheliomatous hyperplasia above abscesses a Blastomycosis: ∼8–30 μm yeast form (arrow) b Chromomycosis: ∼5–12 μm Medlar bodies c Coccidioidomycosis: ∼80–200 μm spherules with endospores

19

Note Paracoccidioidomycosis (∼6–60 μm mariner’s wheel; an uncommon infection in the USA), sporotrichosis (organisms usually not evident in biopsies), and tuberculosis verrucosa cutis may also show this pattern

Key differences

22

Shape on Low Power

Proliferation downward from epidermis

• Proliferation downward from epidermis • Strands of basaloid cells in a fibrovascular stroma often emanating from strands of squamous epithelium • Some hints of palisading of cells (arrow)

20 Fibroepithelioma of Pinkus

Shape on Low Power


23

• Proliferation downward from epidermis • Fibrotic stroma adjacent to the hair follicle has reticulated strands of epithelium • This entity has overlap with trichodiscoma (some consider these a spectrum of the same entity)

21

Fibrofolliculoma

24

Shape on Low Power


• Proliferation downward from epidermis • Normal-appearing keratinocytes with some arranged in squamous eddies

22 Inverted follicular keratosis

Shape on Low Power


25

• Proliferation downward from epidermis • Sebaceous glands, basaloid proliferations (arrow) connect to the epidermis • Apocrine glands may be seen deep • Absent terminal hairs in mature stage

23

Nevus sebaceus of Jadassohn

26

Shape on Low Power


• Proliferation downward from epidermis • Uniform blue cells with interspersed ducts (arrows) • Fibrotic or hyalinized stroma with dilated vessels

24 Poroma

Shape on Low Power


27

• Proliferation downward from epidermis • Reticulated strands of banal keratinocytes, often pigmented • Interspersed pseudohorn cysts

25

Seborrheic keratosis, reticulated

28

Shape on Low Power


• Proliferation downward from epidermis • Proliferation composed of pale/clear cells • Peripheral palisading (long arrow) with thickened basement membrane (short arrow)

26 Trichilemmoma

Shape on Low Power


29

• Proliferation downward from epidermis • Pale cells in columns with “windows” of dermis in between • Peripheral palisading

27

Tumor of the follicular infundibulum

30

Shape on Low Power


(a)

(b)

(c)

(d)

Proliferation downward from epidermis a Fibroepithelioma of Pinkus: strands of basaloid epithelium in fibrovascular stroma b Fibrofolliculoma: hair follicle with adjacent fibrotic stroma and reticulated epithelium

28 Key differences

c Inverted follicular keratosis: squamous eddies of normal keratinocytes d Nevus sebaceus: proliferation of epidermis connecting to sebaceous lobules and basaloid proliferations

Shape on Low Power

(e)

(f)

(g)

(h)

Proliferation downward from epidermis (cont.) e Poroma: uniform blue cells with interspersed ducts f Seborrheic keratosis, reticulated: reticulated strands of banal keratinocytes, often pigmented; interspersed pseudohorn cysts


31

g Trichilemmoma: pale/clear keratinocytes with peripheral palisading and thickened basement membrane h Tumor of the follicular infundibulum: pale cells in columns with “windows” of dermis in between

Key differences

32

Shape on Low Power

• Central pore • Invaginated epidermis is acanthotic

29 Dilated pore of Winer

Central pore

Shape on Low Power

Central pore

33

• Central pore • Invaginated epidermis is acanthotic and has areas resembling outer root sheath with peripheral palisading around slightly pale cells (arrows)

30

Pilar sheath acanthoma

34

Shape on Low Power

Central pore

• Central pore • Invaginated epidermis connects to a primary hair follicle • Multiple secondary hair follicles radiating away from the central follicle

31 Trichofolliculoma

Shape on Low Power

(a)

Central pore

35

(b)

(c)

Central pore a Dilated pore of Winer: acanthotic epidermis b Pilar sheath acanthoma: epidermal acanthosis and areas resembling outer root sheath c Trichofolliculoma: primary follicle and surrounding secondary follicles

32

Key differences

36

Shape on Low Power

Palisading reactions

• Palisading of histiocytes around amorphous white-gray substance with a feathery edge

36 Gout

Shape on Low Power


37

• Palisading of histiocytes around altered collagen, basophilic mucin (long arrow) • Lymphocytes around vessels (short arrow)

37

Granuloma annulare

38

Shape on Low Power


• Palisading of histiocytes and bizarre, multinucleated giant cells around foci of necrosis • Scattered Touton giant cells • Cholesterol clefts, plasma cells, and/or lymphoid follicles may be present

38 Necrobiotic xanthogranuloma

Shape on Low Power


39

• Palisading of histiocytes around central pink fibrin • The reaction is often deep

39

Rheumatoid nodule

40

Shape on Low Power


(a)

(b)

(c)

(d)

(e)

Palisading reactions a Gout: central white-gray feathery material b Granuloma annulare: central altered collagen interspersed with blue mucin c Rheumatoid nodule: central pink fibrin

40 Key differences

d Necrobiosis lipoidica: altered collagen surrounded by giant cells, plasma cells e Necrobiotic xanthogranuloma: bizarre, multinucleated giant cells; Touton giant cells

Shape on Low Power

Space with a lining

41

• Space with a lining • Lining composed of an inner layer of cells with decapitation secretion (long arrow) and a compressed layer of myoepithelial cells (short arrow)

41

Apocrine hidrocystoma

42

Shape on Low Power

Space with a lining

• Space with a lining • “Lining” is not a true epithelial layer but is cartilage • Centrally, there is degeneration of cartilage

42 Auricular pseudocyst

Shape on Low Power

Space with a lining

43

• Space with a lining • Lining composed of squamous or sometimes cuboidal/ columnar epithelium often with squamous metaplasia • Prominent lymphoid follicles in wall

43

Branchial cleft cyst

44

Shape on Low Power

Space with a lining

• Space with a lining • Lining composed of cuboidal/columnar epithelium with cilia (arrows)

44 Cutaneous ciliated cyst

Shape on Low Power

Space with a lining

45

• Space with a lining • Spaces embedded in a fibrovascular stroma (endometrial stroma) • Lining composed of crowded blue cells • Hemosiderin deposits common in stroma

45

Cutaneous endometriosis

46

Shape on Low Power

Space with a lining

• Space with a lining • Lining composed of squamous epithelium • Walls contain adnexal structures

46 Dermoid cyst

Shape on Low Power

Space with a lining

47

• Space with a lining • Lining composed of squamous epithelium with a granular layer (arrow) • Cyst contents composed of flakes of keratin

47

Epidermal inclusion cyst

48

Shape on Low Power

Space with a lining

• Space with a lining • Lining composed of squamous epithelium without a granular layer • Cyst contents composed of dense pink keratin

48 Pilar cyst

Shape on Low Power

Space with a lining

49

• Space with a lining • Lining composed of layered epithelium with bright pink crenulated keratin (arrow) • Sebaceous glands in wall

49

Steatocystoma

50

Shape on Low Power

Space with a lining

(a)

(b)

(c)

(d)

(e)

Space with a lining a Apocrine hidrocystoma: decapitation secretion b Auricular pseudocyst: degeneration surrounded by cartilage

50 Key differences

c Branchial cleft cyst: prominent lymphoid follicles in wall d Cutaneous ciliated cyst: columnar epithelium with cilia; no structures in wall e Cutaneous endometriosis: fibrovascular stroma with glands

Shape on Low Power

(f)

(g)

(h)

(i)

Space with a lining

51

(j)

Space with a lining (cont.) f Dermoid cyst: sebaceous glands and other adnexal structures in wall g Epidermal inclusion cyst: epithelium with granular layer, flakes of keratin in center h Glomangioma (glomuvenous malformation): monomorphous, cuboidal blue cells i Pilar cyst: epithelium without granular layer, dense keratin in center

j Steatocystoma: crenulated keratin lining the cyst; sebaceous glands in wall Note Bronchogenic cysts are uncommon, and are diagnosed by clinical history and the presence of columnar epithelium with/without cilia, with/without cartilage in the wall; venous lakes are common and are composed of flattened endothelial cells with erythrocytes in the space

Key differences

52

Shape on Low Power

Epidermal perforation

• Epidermal perforation • Elongated claw (epidermal rete) gripping thin, glassy, eosinophilic elastic fibers and debris • Altered elastic fibers are thinner than the collagen fibers in the dermis

33 Elastosis perforans serpiginosa

Shape on Low Power


53

• Epidermal perforation • Shallow cup-shaped architecture • Pink collagen fibers extend vertically through epidermis

34

Reactive perforating collagenosis

54

Shape on Low Power


(a)

(b)

(c)

Epidermal perforation a Elastosis perforans serpiginosis: elongated rete forming a claw (tortuous channel) b Reactive perforating collagenosis: shallow, broad, cupshaped architecture

35 Key differences

c Calcinosis cutis, perforating: chunky, bluish material at the base of an ulcer Note Other entities may also perforate the epidermis, e.g., chondrodermatitis nodularis helicis, pseudoxanthoma elasticum, granuloma annulare

Shape on Low Power

• • • • •

51

Cords and tubules

55

Cords and tubules in dermis Numerous horn cysts (long arrow) in fibrotic stroma Tubules of two-layered epithelium (short arrow) Calcification often present Confined to dermis

Desmoplastic trichoepithelioma

56

Shape on Low Power

Cords and tubules

• Cords and tubules in dermis • Tubules of single-layered (“Indian filing”; long arrow) and multilayered epithelium • Some cells forming gland-like structures (short arrow) • Other metastatic carcinomas may look like this: need clinical history; immunohistochemistry may be helpful

52 Metastatic breast carcinoma

Shape on Low Power

Cords and tubules

57

• Cords and tubules in dermis • Tubules of epithelium connect to islands of epithelium with duct-like spaces • Deeply infiltrative (fills dermis) • Perineural involvement

53

Microcystic adnexal carcinoma

58

Shape on Low Power

Cords and tubules

• Cords and tubules in dermis • Tubules of epithelium composed of basaloid cells with hints of peripheral palisading • New collagen forming around islands (arrow) • Deeply infiltrative

54 Morpheaform basal cell carcinoma

Shape on Low Power

• Cords and tubules in dermis • Restricted to upper dermis • “Tadpoles” of epithelium with duct-like structures in heads (arrow)

55

Cords and tubules

59

• Darker cells at periphery, clear cells in center • Eosinophilic cuticle lining lumina • No horn cysts

Syringoma

60

Shape on Low Power

Cords and tubules

(a)

(b)

(c)

(d)

(e)

Cords and tubules a Desmoplastic trichoepithelioma: horn cysts, no clear cells, circular areas of epithelium surround keratin b Metastatic breast carcinoma: single-filing of atypical cells, deeply infiltrative c Microcystic adnexal carcinoma: like syringoma with tadpole-like structures but deeply infiltrative, perineural involvement

56 Key differences

d Morpheaform basal cell carcinoma: infiltrative cords of basaloid cells with hints of peripheral palisading; may have some duct-like structures (but less than c) e Syringoma: superficial tadpoles with clear cells

Shape on Low Power

Papillated dermal tumor

61

• Papillated dermal tumor • Disordered layers of epithelium in large papillations with some tubules • Variable cytological atypia and mitotic figures • Acral location

57

Aggressive digital papillary adenocarcinoma

62

Shape on Low Power


• Papillated dermal tumor • Nipple may be identified by prominent fascicles of smooth muscle in dermis (not pictured) • Circular islands, some cystic, and tubules • Compressed myoepithelial cells at periphery of islands/ tubules

• Decapitation secretion often evident • Resembles syringocystadenoma papilliferum (but fewer plasma cells) or tubular apocrine adenoma

58 Florid papillomatosis (erosive adenomatosis) of the nipple (nipple adenoma)

Shape on Low Power


63

• Papillated dermal tumor • Finger-like projections have cores of collagen/fibroblasts (arrow) • No connection to epidermis

59

Hidradenoma papilliferum

64

Shape on Low Power


• Islands of epithelium with papillated projections • With or without epidermal connection

60 Papillary eccrine adenoma

Shape on Low Power


65

• Papillated dermal tumor • Papillations contain numerous plasma cells (arrow) • Tumor often connected to epidermis

61

Syringocystadenoma papilliferum

66

Shape on Low Power


• Papillated dermal tumor • Evidence of decapitation secretion • Overlaps with papillary eccrine adenoma

62 Tubular apocrine adenoma

Shape on Low Power

(a)

(b)

(c)

(d)

(e)

(f)

Papillated dermal tumor a Aggressive digital papillary adenocarcinoma: large tumor, atypical cells, and mitoses piled up b Florid papillomatosis (erosive adenomatosis) of the nipple (nipple adenoma): resembles syringocystadenoma papilliferum but fewer plasma cells; nipple may be identified by smooth muscle bundles in dermis

63


67

c Hidradenoma papilliferum: thin papillations with fibrovascular cores d Papillary eccrine adenoma: islands of epithelium with papillated areas e Syringocystadenoma papilliferum: fat papillations with plasma cells in cores f Tubular apocrine adenoma: decapitation secretion and papillations within islands

Key differences

68

• • • •

Shape on Low Power

(Suggestion of) vessels

(Suggestion of) vessels Circular pink mass in dermis Scar-like appearance Mass composed of smooth muscle cells (cigar-shaped nuclei; long arrow) with compressed vessels (short arrows) (sometimes dilated)

64 Angioleiomyoma

Shape on Low Power


69

• (Suggestion of) vessels • Numerous vessels with epithelioid (“hobnail”) endothelial cells (arrow) surrounded by inflammation • Clusters of epithelioid endothelial cells may mimic granulomas • Eosinophils may be prominent

65

Angiolymphoid hyperplasia with eosinophilia

70

Shape on Low Power


• (Suggestion of) vessels • Maze-like arrangement of vessels lined by atypical cells • Deeply infiltrative

66 Angiosarcoma

Shape on Low Power


71

• (Suggestion of) vessels • Superficial vessels surrounded by plasma cells and “clouds” of organisms (arrow) that stain with silver

67

Bacillary angiomatosis

72

Shape on Low Power


• (Suggestion of) vessels • Hyperkeratosis • Central erosion/ulceration of epidermis (not always present) with underlying pink fibrin and flanking vessels • Vascular ectasia with plump endothelial cells • Cartilage may be present beneath fibrin

68 Chondrodermatitis nodularis helicis

Shape on Low Power

• • • •

69


73

(Suggestion of) vessels Fibrotic stroma Concentric fibrosis around vessels/adnexae (long arrow) Stellate fibroblasts (short arrows)

Fibrous papule

74

Shape on Low Power


• (Suggestion of) vessels • Vessels forming around other vessels (promontory sign) • Vessels may be lined by inconspicuous endothelial cells

70 Kaposi sarcoma, patch/plaque

Shape on Low Power


75

• (Suggestion of) vessels • Lobules of dilated vessels embedded in loose stroma with inflammatory cells

71

Pyogenic granuloma

76

Shape on Low Power

• • • •


(Suggestion of) vessels Hyperkeratosis Variable spongiosis Small-caliber, thick-walled capillaries in clusters in the upper dermis (arrows) • Hemosiderin

72 Stasis dermatitis

Shape on Low Power


77

• (Suggestion of) vessels • Somewhat wedge-shaped arrangement of vessels • Hemosiderin (arrow) around the peripheral vessels

73

Targetoid hemosiderotic (hobnail) hemangioma

78

Shape on Low Power


(a)

(b)

(c)

(d)

(e)

(Suggestion of) vessels a Angioleiomyoma: well-circumscribed pink circle composed of cigar-shaped spindle cells and compressed to dilated vessels b Angiolymphoid hyperplasia with eosinophilia: dilated vessels with prominent hobnail endothelial cells surrounded by inflammation, with/without numerous eosinophils

74 Key differences

c Angiosarcoma: maze-like connection of vessels lined by atypical cells d Bacillary angiomatosis: dilated vessels surrounded by inflammation that includes plasma cells and ill-defined “clouds” e Chondrodermatitis nodularis helicis: dilated vessels on either side of fibrin; epidermis may be eroded/ulcerated or acanthotic/atrophic

Shape on Low Power

(f)

(g)

(h)

(i)


79

(j)

(Suggestion of) vessels (cont.) f Fibrous papule: fibrotic stroma with stellate fibroblasts and dilated vessels g Kaposi sarcoma, patch/plaque: slit-like or angulated spaces dissecting through collagen; vessels around vessels h Pyogenic granuloma: clusters of dilated vessels surrounded by mixed inflammation

i Stasis dermatitis: small clusters of capillaries in upper dermis with hemosiderin j Targetoid hemosiderotic (hobnail) hemangioma: wedgeshaped area of increased vessels (dilated superficially) with hemosiderin at periphery

Key differences

80

Shape on Low Power

Circular dermal islands

• Circular dermal islands • Islands contain basaloid cells with a cribriform pattern of duct-like spaces filled with amorphous material

75 Adenoid cystic carcinoma

Shape on Low Power


81

• Circular dermal islands • Islands contain basaloid cells surrounded by a thick pink basement membrane (arrow) • Islands arranged like a “jigsaw puzzle”

76

Cylindroma

82

Shape on Low Power


• Circular dermal islands • Islands of epithelium with central flaky keratin (horn cysts) • Basaloid tubules in stroma and coming off cysts

77 Trichoadenoma

Shape on Low Power

(a)


83

(b)

(c)

Circular dermal islands a Adenoid cystic carcinoma: cribriform pattern of duct-like structures b Cylindroma: puzzle-like arrangement, thick/pink basement membrane c Trichoadenoma: numerous horn cysts

78

Key differences



2

Top-Down • Hyperkeratosis/parakeratosis, 87 • Upper epidermal change, 98 • Acantholysis, 108 • Eosinophilic spongiosis, 118 • Subepidermal space/cleft, 124 • Perivascular infiltrate, 131 • Band-like upper dermal infiltrate, 136 • Interface reaction, 141 • Granular “material” in cells, 148 • “Busy” dermis, 153 • Dermal material, 156 • Change in the fat, 168


Top-Down

• • • •

Hyperkeratosis/parakeratosis and lymphocytic infiltrate Follicular plugging Thinned epidermis Vacuolar change at dermoepidermal junction

Hyperkeratosis/parakeratosis

87

• Thickened basement membrane • Pigment incontinence • Periadnexal and perivascular lymphocytic infiltrate

Discoid lupus erythematosus

88

Top-Down


• Hyperkeratosis/parakeratosis and lymphocytic infiltrate • Scattered “dyskeratotic” keratinocytes may be present • Slightly acanthotic epidermis

Flegel disease

Top-Down

• • • •


89

Hyperkeratosis/parakeratosis and lymphocytic infiltrate Vacuolar change at dermoepidermal junction Pink homogenization of papillary dermis Underlying band-like inflammatory infiltrate

Lichen sclerosus et atrophicus

90

Top-Down


• Hyperkeratosis/parakeratosis (cornoid lamellae) and lymphocytic infiltrate • Cornoid lamellae (tiered parakeratosis above altered granular layer) (arrow) • A lichenoid infiltrate may be present

Porokeratosis

Top-Down


91

• Hyperkeratosis alternating with parakeratosis • Acanthotic epidermis

Inflammatory linear verrucous epidermal nevus

92

Top-Down


• Hyperkeratosis alternates with parakeratosis in a checkerboard pattern • Follicular plugging • Irregular acanthosis of epidermis

Pityriasis rubra pilaris

Top-Down


93

• Hyperkeratosis alternating with parakeratosis (alternating pink and blue stratum corneum) • Beneath parakeratosis, atypical keratinocytes in lower epidermis • Orthokeratosis above banal keratinocytes in adnexal structures

Actinic keratosis

94

Top-Down


• Parakeratosis with granules • Granules retained in the stratum corneum (arrows)

Axillary granular parakeratosis

Top-Down


95

• Parakeratosis with organisms • Slightly refractile organisms (spheres and tubules) in stratum corneum • Parakeratosis may be seen above orthokeratosis (“sandwich sign”) • Obvious organisms on periodic acid–Schiff (PAS) (arrows)

Dermatophytosis

96

Top-Down


(a)

(b)

(c)

(d)

(e)

Hyperkeratosis/parakeratosis and lymphocytic infiltrate a Discoid lupus erythematosus: follicular plugging, thickened basement membrane, periadnexal inflammation b Flegel disease: hyperkeratosis over slight acanthosis, variable inflammation c Lichen sclerosus et atrophicus: pink homogenized papillary dermis with underlying inflammation

Key differences

Hyperkeratosis/parakeratosis, alternating d Actinic keratosis: alternating pink and blue stratum corneum above buds of atypical keratinocytes and banal keratinocytes in spared adnexal structures e Inflammatory linear verrucous epidermal nevus: hyperkeratosis alternating with parakeratosis over acanthosis

Top-Down

(f)

(g)

(h)

(i)


97

(j)

f Pityriasis rubra pilaris: checkerboard parakeratosis and hyperkeratosis, irregular acanthosis Hyperkeratosis/parakeratosis with: g Axillary granular parakeratosis: retained granules in stratum corneum h Dermatophytosis: circles and linear hyphae in stratum corneum

i Nutritional deficiency: upper epidermal parakeratosis/ necrosis with pallor j Psoriasis: neutrophils Note Tinea versicolor is in the differential; dermatophytosis and tinea versicolor may be subtle and appear like “normal” skin on low power

Key differences

98

Top-Down

Upper epidermal change

• Upper epidermal change of nests of keratinocytes • Nests are composed of monomorphous, typical keratinocytes

Clonal seborrheic keratosis

Top-Down


99

• Upper epidermal change of keratinocytes with blue-gray expanded cytoplasm and haloes around nuclei

Epidermodysplasia verruciformis

100

Top-Down


• Upper epidermal change of prominent keratohyaline granules and chicken-wire cell membranes: granular– vacuolar change (arrows)

Epidermolytic hyperkeratosis

Top-Down


101

• Upper epidermal change of koilocytes with very prominent keratohyaline granules • Angular, clumped tonofilaments in cytoplasm

Myrmecium

102

Top-Down


• Upper epidermal change of reticular degeneration (edema of the cells with retention of cell membranes) and pink intracytoplasmic globules (arrows) • Usually acral skin

Orf

Top-Down


103

• Upper epidermal change of scattered large cells singly and in nests • May be able to see a compressed basal layer beneath nests (eyeliner) • Large cells have expanded cytoplasm and nuclei at periphery

Paget disease

104

Top-Down


• Upper epidermal change of koilocytes: cells with haloes around nuclei • Epidermal surface is only slightly papillated

Verruca plana

Top-Down


105

• Upper epidermal change of koilocytes • Epidermal surface papillated • Toeing-in (arborization) of rete ridges

Verruca vulgaris

106

Top-Down


(a)

(b)

(c)

(d)

Upper epidermal change a Acantholysis: rounding up and separation of individual keratinocytes b Clonal seborrheic keratosis: nests of typical, monomorphous keratinocytes

Key differences

c Epidermodysplasia verruciformis: expanded blue-gray cytoplasm, some perinuclear haloes d Epidermolytic hyperkeratosis: strung-out cell membranes, loss of nuclei, granular–vacuolar change

Top-Down

(e)

(f)

(g)

(h)

Upper epidermal change (cont.) e Myrmecium: very prominent keratohyaline granules and intracytoplasmic, angular inclusions f Orf: reticular degeneration (pink cell membranes with loss of nuclei) with scattered inclusions


107

g Paget disease: scattered cells that lack intercellular bridges with prominent grayish cytoplasm h Verruca: koilocytes

Key differences

108

Top-Down

Acantholysis

• Benign acantholytic dyskeratosis with corp ronds (long arrow) and grains (short arrow) • Parakeratosis above the acantholytic dyskeratosis

Darier disease

Top-Down

Acantholysis

109

• Benign acantholytic dyskeratosis in small foci • Also foci of spongiosis, acantholysis without dyskeratosis (Hailey–Hailey pattern and pemphigus patterns)

Grover disease

110

Top-Down

Acantholysis

• Benign acantholysis (sometimes with dyskeratosis) in full thickness to two-thirds of the epidermis • Resembles a “dilapidated brick wall”

Hailey–Hailey disease

Top-Down

Acantholysis

111

• Benign non-dyskeratotic acantholysis with ballooning degeneration • Multinucleated cells with rimming of chromatin • Follicular necrosis/acantholysis is a clue

Herpes virus infection

112

Top-Down

Acantholysis

• Benign acantholysis in the upper stratum spinosum, making the granular layer appear altered • May see “cling-ons” (acantholytic cells on roof of split)

Pemphigus foliaceus

Top-Down

Acantholysis

113

• Benign acantholysis above the basal layer • Basal layer intact and appears like “tombstones”

Pemphigus vulgaris

114

Top-Down

Acantholysis

• Malignant dyskeratotic acantholysis in a large, infiltrative tumor • Prominent atypical cells (arrows) and mitoses

Squamous cell carcinoma, adenoid type

Top-Down

Acantholysis

115

• Histologically like Darier disease with corp ronds (long arrow) and grains (short arrow) but may have more prominent cup-shape and/or follicular involvement • Clinically a solitary lesion

Warty dyskeratoma

116

Top-Down

Acantholysis

(a)

(b)

(c)

(d)

Acantholysis a Darier disease: prominent parakeratosis above corp ronds and grains b Grover disease: multiple patterns of acantholysis (Darierlike, Hailey–Hailey-like, pemphigus-like) and spongiosis in small foci

Key differences

c Hailey–Hailey disease: majority of epidermis involved by acantholysis d Herpes virus infection: ballooning degeneration, multinucleated cells with chromatin rimming

Top-Down

(e)

(f)

(g)

(h)

Acantholysis (cont.) e Pemphigus foliaceus: granular layer prominent with acantholysis f Pemphigus vulgaris: acantholysis above tombstoned basal layer; follicles may be involved

Acantholysis

117

g Squamous cell carcinoma: acantholysis and squamous pearls, atypical keratinocytes, and mitoses (malignant dyskeratotic acantholysis) h Warty dyskeratoma: cup-shaped area of acantholysis and dyskeratosis, villi at base

Key differences

118

Top-Down

Eosinophilic spongiosis

• Eosinophilic spongiosis • Vesicles within epidermis may be prominent

Allergic contact dermatitis

Top-Down


119

• Eosinophilic spongiosis • Wedge-shaped pattern of inflammation on low-power view • Vesicles within epidermis may be prominent

Arthropod bite reaction

120

Top-Down


• Eosinophilic spongiosis • Dyskeratotic keratinocytes (bottom arrow) in addition to eosinophils (top arrow)

Incontinentia pigmenti

Top-Down


121

• Eosinophilic abscesses within epidermis • Acantholysis may be absent to subtle • Hyperplastic epidermis

Pemphigus vegetans

122

Top-Down


• Eosinophilic spongiosis • Mites, scybala, eggs within stratum corneum

Scabies

Top-Down

(a)

(b)

(c)

(d)

(e)

(f)

Eosinophilic spongiosis a Allergic contact dermatitis: orderly vesicles and eosinophils in epidermis b Arthropod bite reaction: superficial and deep infiltrate, may see prominent vesicles c Bullous pemphigoid: eosinophils lining up at junction


123

d Incontinentia pigmenti: eosinophilic spongiosis with dyskeratotic cells e Pemphigus vegetans: eosinophilic abscesses within acanthotic epidermis f Scabies: mites/scybala/eggs in stratum corneum

Key differences

124

Top-Down

Subepidermal space/cleft

• Subepidermal space (can appear intraepidermal) • Thin grenz zone (arrow) • Endothelial cell-lined spaces filled with erythrocytes

Angiokeratoma

Top-Down


125

• Subepidermal space • Eosinophils (arrows) are prominent at the base • May see festooning (papillated bulla base)

Bullous pemphigoid/pemphigoid (herpes) gestationis

126

Top-Down


• Subepidermal space • Neutrophils (arrows) are prominent at the base • May see clusters of neutrophils in papillae adjacent to blister. Note that this same histologic pattern can be seen with linear IgA disease, neutrophil-rich bullous pemphigoid,

Dermatitis herpetiformis

bullous lupus erythematosus, and epidermolysis bullosa acquisita • May see reverse festooning (papillated inferior surface of bulla roof)

Top-Down


127

• Subepidermal space with internal papillations • Thin grenz zone (long arrow) • Spaces lined by endothelial cells (short arrow) and may contain a few erythrocytes

Lymphangioma

128

Top-Down


• Subepidermal space (edema) • Superficial and deep vessels surrounded by lymphocytes

Polymorphous light eruption

Top-Down

• • • • •

Subepidermal space Non-inflammatory base Festooning of papillary dermis Thickened vessel walls (long arrow) Caterpillar bodies in epidermis (short arrow)


129

Note Differential diagnosis of a non-inflammatory subepidermal bulla includes non-inflammatory bullous pemphigoid, epidermolysis bullosa acquisita, diabetic bullae, and epidermolysis bullosa subtypes

Porphyria cutanea tarda

130

Top-Down


(a)

(b)

(c)

(d)

(e)

(f)

Subepidermal space/cleft a Angiokeratoma: erythrocytes fill spaces lined by endothelial cells b Bullous pemphigoid: eosinophils at base c Dermatitis herpetiformis: neutrophils at base, reverse festooning

Key differences

d Lymphangioma: spaces lined by endothelial cells and are empty e Polymorphous light eruption: perivascular lymphocytes f Porphyria cutanea tarda: non-inflammatory base, festooning, caterpillar bodies

Top-Down

Perivascular infiltrate

131

• Superficial and deep perivascular infiltrate of lymphocytes • Lymphocytes tightly cuffed around vessels Note Differential includes polymorphous light eruption (classically has dermal edema), see page 128; Jessner lymphocytic infiltrate; and connective tissue disorders

Gyrate erythema

132

• • • •

Top-Down


Perivascular infiltrate of neutrophils and nuclear debris Alteration/necrosis of collagen (arrow) Extravasated erythrocytes Fibrin within vessels

Leukocytoclastic vasculitis

Top-Down


133

• Superficial perivascular infiltrate of lymphocytes (sometimes minimal) • Extravasated erythrocytes (arrows) • Hemosiderophages

Pigmented purpuric dermatosis

134

• • • •

Top-Down


Superficial perivascular infiltrate of lymphocytes Mounds of parakeratosis (long arrows) Mild epidermal spongiosis (short arrow) Extravasated erythrocytes

Pityriasis rosea

Note Guttate psoriasis is in the differential; guttate psoriasis is favored if there are neutrophils in the mounds of parakeratosis

Top-Down

(a)

(b)

(c)

(d)


135

(e)

Superficial perivascular infiltrate a Granuloma annulare: perivascular lymphocytes; interstitial/ palisaded histiocytes around mucin b Gyrate erythema: tightly cuffed superficial and deep perivascular infiltrate of lymphocytes, epidermis is normal c Leukocytoclastic vasculitis: dermis looks “messy” on low power with perivascular neutrophils and nuclear debris, pink donuts of degenerated collagen, extravasated erythrocytes

d Pigmented purpuric dermatosis: perivascular (to lichenoid) infiltrate of lymphocytes, extravasated erythrocytes, hemosiderophages e Pityriasis rosea: mounds of parakeratosis, mild epidermal spongiosis, superficial perivascular infiltrate of lymphocytes, extravasated erythrocytes Note Lymphocytic angiitis describes a pattern of perivascular lymphocytes and is a non-diagnostic finding as many diseases may have such a pattern

Key differences

136

• • • •

Top-Down

Band-like upper dermal infiltrate

Band-like upper dermal infiltrate Infiltrate abuts and involves epidermis Cells in infiltrate have kidney-shaped nuclei (arrows) Eosinophils may be present

Langerhans cell histiocytosis

Top-Down


137

• Band-like upper dermal infiltrate • A grenz zone is usually present • Cells in infiltrate have round nuclei and granular gray-blue cytoplasm (arrows) • Eosinophils may be present

Mastocytosis

138

• • • •

Top-Down


Band-like upper dermal infiltrate Infiltrate abuts and involves epidermis May see Pautrier microabscesses Cells in infiltrate have atypical nuclei (arrows)

Mycosis fungoides

Top-Down


139

• Band-like upper dermal infiltrate • Atrophic epidermis of diamond-shaped keratinocytes with intercellular edema • Dermal infiltrate of plasma cells

Zoon balanitis (balanitis circumscripta plasmacellularis)

140

Top-Down


(a)

(b)

(c)

(d)

Band-like upper dermal infiltrate a Langerhans cell histiocytosis: kidney-shaped nuclei b Mastocytosis: round nuclei and slightly granular cytoplasm c Mycosis fungoides: cells in infiltrate have atypical nuclei, vacuolar change, fibrosis in dermis, lining up of lymphocytes at dermoepidermal junction

Key differences

d Zoon balanitis: diamond-shaped keratinocytes with underlying plasma cells Note Lichenoid processes are also band-like; see page 147

Top-Down

• • • • •

Interface reaction

141

Lichenoid infiltrate Numerous necrotic keratinocytes Incontinence of pigment Deep perivascular infiltrate Infiltrate is mixed with eosinophils and neutrophils

Fixed drug reaction

142

Top-Down

Interface reaction

• Vacuolar change at dermoepidermal junction • Necrotic keratinocytes (arrows) in epidermis and follicles with adjacent lymphocytes (satellite cell necrosis)

Graft-versus-host disease

Top-Down

Interface reaction

143

• Lichenoid infiltrate that is the “ball” being held by fingers of epidermis (the “claw”) • Infiltrate is composed of lymphocytes and histiocytes and occasional giant cells

Lichen nitidus

144

• • • • • • •

Top-Down

Interface reaction

Lichenoid infiltrate Hyperkeratosis, irregular acanthosis, hypergranulosis Saw-toothing of basal layer Colloid bodies, Civatte bodies Pigment incontinence Usually no eosinophils If a mucosal surface, plasma cells may be present

Lichen planus

Note Lichenoid drug reactions can look the same but usually show parakeratosis and eosinophils Note Benign lichenoid keratosis can look the same (need clinical history)

Top-Down

Interface reaction

145

• Lichenoid infiltrate and deep perivascular/periadnexal infiltrate • Peri-eccrine lymphocytic infiltrate is a clue • Scattered (high and low) necrotic keratinocytes

Lichen striatus

146

Top-Down

Interface reaction

• Lichenoid and deep perivascular lymphocytic infiltrate (wedge-shaped on low power) • Parakeratosis • Erythrocytes in the epidermis and extravasated in the dermis • Necrosis of the epidermis (sometimes present)

Pityriasis lichenoides et varioliformis acuta

Top-Down

(a)

(b)

(c)

(d)

(e)

(f)

Interface reaction a Fixed drug reaction: lichenoid and deep perivascular mixed infiltrate with eosinophils, linear necrosis of basal cells b Graft-versus-host disease: vacuolar change with scattered necrotic keratinocytes in epidermis and hair follicles (satellite cell necrosis) c Lichen nitidus: ball of lymphocytes and histiocytes in the dermis held by an epidermal claw

Interface reaction

147

d Lichen planus: lichenoid infiltrate, hyperkeratosis, hypergranulosis, saw-toothed base of acanthotic epidermis e Lichen striatus: lichenoid and deep infiltrate that involves eccrine glands, scattered necrotic keratinocytes f Pityriasis lichenoides et varioliformis acuta: parakeratosis, necrotic epidermis, extravasated erythrocytes, lichenoid and deep lymphocytic infiltrate

Key differences

148

• • • •

Top-Down

Granular “material” in cells

Granular “material” in histiocytes Fine, bluish granules of similar size Large blue-purple collagen “concretions” (arrow) An adjacent scar is often evident

Aluminum chloride (Drysol solution)

Top-Down


149

• Granular “material” in histiocytes and extracellularly • Similar in staining quality to hemosiderin • Larger collagen “concretions” of brown-yellow to black material may be present • An adjacent scar is often evident

Ferric subsulfate (Monsel solution)

150

Top-Down


• Granular “material” in histiocytes (hemosiderophages) • Yellow-brown, refractile globules and granules of varying sizes • Appears green-yellow with microscope condenser lowered • Extravasated erythrocytes may be present

Hemosiderin

Top-Down


151

• Granular “material” in melanocytes and melanophages • Brown, fine granules of similar size within nested (clustered) melanocytes with smaller cells toward base with individual cells splaying through collagen • Appears darker brown to black with microscope condenser lowered

Melanin (in an intradermal nevus)

152

Top-Down


(a)

(b)

(c)

(d)

(e)

(f)

Granular “material” in cells a Aluminum chloride (Drysol solution): presence of a scar with adjacent histiocytes containing fine, bluish granules; blue-purple collagen “concretions” b Ferric subsulfate (Monsel solution): presence of a scar with adjacent histiocytes containing brown-yellow pigment; brown-yellow to black collagen “concretions”

Key differences

c Hemosiderin: variably sized, refractile globules and granules of yellow-brown pigment d Melanin: non-refractile, similarly sized circles of brown pigment e Leishmaniasis: dot-like bluish organisms within sheets of histiocytes; scattered plasma cells f Tattoo: black particles free in dermis and within macrophages

Top-Down

“Busy” dermis

153

• “Busy” dermis • Spindle cells with oval to round nuclei in clusters and splaying through sclerotic collagen • Occasional cells with melanin pigment (arrows)

Blue nevus, hypopigmented

154

Top-Down

“Busy” dermis

• “Busy” dermis • Dense collagen with hyperchromatic cells interstitially • Hyperchromatic cells display nuclear molding

Metastatic breast carcinoma, interstitial pattern (carcinoma en cuirasse)

Top-Down

(a)

(b)

(c)

(d)

(e)

(f)

“Busy dermis” a Blue nevus, hypopigmented: occasional cells with melanin pigment b Dermatofibroma: collagen entrapment c Granuloma annulare: subtle hints of palisading, increased mucin

“Busy” dermis

155

d Kaposi sarcoma: increased vessels e Leukemia cutis: atypical cells with granular cytoplasm f Metastatic breast carcinoma, interstitial pattern: hyperchromatic nuclei with molding

Key differences

156

Top-Down

Dermal material

• Dermal material that is pink and amorphous, diffuse and perivascular • Plasma cells (arrows) are often present around vessels

Amyloidosis, nodular

Top-Down

Dermal material

157

• Dermal material that is blue-purple and chunky Note Calcium deposits can be seen in adnexal tumors (trichoepithelioma, pilomatricoma) Note Calcium may be deposited on the altered elastic fibers in pseudoxanthoma elasticum; see page 164

Calcinosis cutis

158

Top-Down

Dermal material

• Dermal material that is pink and amorphous and fills the upper half of the dermis • Early lesions have pink material around vessels

Erythropoietic protoporphyria

Top-Down

Dermal material

159

• Dermal material that is bluish, curvy and ribbon-like

Gel foam

160

Top-Down

Dermal material

• Dermal material that is pink and amorphous, often filling the dermis full thickness • May be perpendicular to epidermis and around adnexae and vessels

Lipoid proteinosis

Top-Down

Dermal material

161

• Dermal material that is banana-shaped and brown-orange (arrows)

Ochronosis

162

Top-Down

Dermal material

• Dermal material • Bright, dense pink trabeculae with nuclei with haloes around them (osteocytes) Note Pilomatricomas can be ossified

Osteoma cutis

Top-Down

Dermal material

163

• Dermal material that is lost during processing and is “seen” as irregularly shaped circular spaces (arrows) • Dark pink sclerotic stroma • Swiss-cheese appearance

Paraffinoma

164

Top-Down

Dermal material

• Dermal material that is blue and squiggly (arrows) • Sometimes the corkscrew fibers are calcified

Pseudoxanthoma elasticum

Top-Down

Dermal material

165

• Dermal material that is black (most commonly) and is free in the dermis as well as within macrophages

Tattoo

166

Top-Down

Dermal material

(a)

(b)

(c)

(d)

(e)

Dermal material a Amyloidosis, nodular: amorphous pink material with plasma cells b Calcinosis cutis: blue-purple chunks c Erythropoietic protoporphyria: amorphous pink material around vessels and in upper dermis

Key differences

d Gel foam: blue interconnected ribbons e Lipoid proteinosis: amorphous pink material filling the entire dermis; often around adnexae

Top-Down

(f)

(g)

(h)

(i)

Dermal material

167

(j)

Dermal material (cont.) f Ochronosis: brown-orange banana shapes g Osteoma cutis: well-defined pink shapes with nuclei h Paraffinoma: irregular circular spaces like Swiss cheese

i Pseudoxanthoma elasticum: squiggly blue lines j Tattoo: black particles within macrophages and free in dermis

Key differences

168

Top-Down

Change in the fat

• Change in the fat • Lobular panniculitis with mixed inflammation (histiocytes, lymphocytes, neutrophils) • Inflammation around vessels (vasculitis) in the septae • “Panniculitis > vasculitis”; compare with polyarteritis nodosa; see page 173

Erythema induratum

Top-Down

Change in the fat

169

• Change in the fat • Septal panniculitis with thickened septae between lobules of adipocytes • Septae contain giant cells (short arrow) • Early lesions may have neutrophils, eosinophils • Miescher radial granuloma may be seen (long arrow)

Erythema nodosum

170

Top-Down

Change in the fat

• Change in the fat • Individual adipocytes are lost and replaced by arabesques of pink, ruffled membranes (lipomembranous fat necrosis) (arrows)

Lipodermatosclerosis

Top-Down

• • • • •

Change in the fat

171

Change in the fat Lymphoplasmacytic infiltrate (lobular panniculitis) Lymphoid follicles may be present Fibrinoid (hyaline) necrosis of fat Later stages show hyalinization of fat (hyaline sclerosis)

Lupus profundus

172

Top-Down

Change in the fat

• Change in the fat • Necrosis of the fat with “ghost-like” shadows of fat cells remaining • Calcification/neutrophils/eosinophils may be present • Septal vessels are inflamed

Pancreatic fat necrosis

Top-Down

Change in the fat

173

• Change in the fat • Septal panniculitis • Often at dermal–subcutis junction, a large vessel is involved with inflammation (vasculitis) (arrow) • “Vasculitis > panniculitis”; compare with erythema induratum; see page 168

Polyarteritis nodosa

174

Top-Down

Change in the fat

• Change in the fat • Lobular panniculitis • Inflammation and radial crystalline shapes (arrows) within fat lobules

Subcutaneous fat necrosis of the newborn

Note Post-steroid panniculitis can look the same Note Sclerema neonatorum also has crystalline shapes but lacks inflammation

Top-Down

Change in the fat

175

• Change in the fat • Lobular involvement of inflammation • Atypical lymphocytes rim fat cells Photographs courtesy of Antonio Subtil, MD

Subcutaneous T-cell lymphoma

176

Top-Down

Change in the fat

(a)

(c)

(b)

(d)

Change in the fat a Erythema nodosum: septal thickening with giant cells (sometimes eosinophils) b Polyarteritis nodosa: vasculitis of a medium-sized vessel, often at the dermal–subcutis junction, “vasculitis > panniculitis”

Key differences

(e)

c Angiolipoma: normal adipocytes, increased numbers of vessels with fibrin d Lipodermatosclerosis: pink arabesques of membranes replacing adipocytes e Subcutaneous T-cell lymphoma: rimming of adipocytes with atypical lymphocytes

Top-Down

Change in the fat

177

(f)

(g)

(h)

Change in the fat (cont.) f Lupus profundus: hyaline fat necrosis, lymphocytic lobular infiltrate g Pancreatic fat necrosis: ghost-like necrosis of fat, with/ without calcification

(i)

h Subcutaneous fat necrosis of the newborn: crystalline shapes and inflammation within fat lobules i Erythema induratum: vasculitis and lobular mixed inflammation, “panniculitis > vasculitis”

Key differences



3

Cell Type • Clear, 181 • Melanocytic, 196 • Spindle, 206 • Giant, 218


Cell Type

Clear

181

• Clear “cells” • The organisms (long arrows) are surrounded by capsules, which are seen in sections as clear spaces (short arrows)

Cryptococcosis, gelatinous

182

Cell Type

Clear

• “Clear” cells • Epidermis may be acanthotic or display pseudoepitheliomatous hyperplasia • Cells are polygonal to oval and contain a granular pink material (phagolysosomes) • Large granules are surrounded by haloes

Granular cell tumor

Cell Type

Clear

183

• “Clear” cells • Cells are adipocytes that are so-called “mulberry” cells, with a net-like vacuolar pattern around the nuclei

Hibernoma

184

Cell Type

Clear

• “Clear” cells • Cells are macrophages that contain the organisms

Leishmaniasis

Cell Type

• “Clear” cells • Cells are histiocytes (“Virchow cells”) that look subtly foamy and are filled with organisms (seen with special stains) • Vacuoles with clusters of organisms (globi)

Clear

185

• On low power, the histiocytes are arranged in linear configurations • Grenz zone present • Nerves may appear thickened

Lepromatous leprosy

186

Cell Type

Clear

• “Clear” cells • Cells are adipocytes, with a peripheral, compressed nucleus (arrow)

Lipoma (left)/angiolipoma (right)

• Normal-appearing adipocytes in lobules with an increased number of small vessels, some containing fibrin (arrows)

Cell Type

• • • •

“Clear” cells Cells are melanocytes that have clear/foamy cytoplasm Cells have atypical nuclei (arrows) Special stains may be generally necessary to confirm the diagnosis

Clear

187

• Look for foci of conventional melanoma or a junctional component

Melanoma, balloon cell

188

Cell Type

Clear

• “Clear” cells • Cells are arranged in lobules with areas of ductal differentiation • Hyalinized collagen often present (arrow)

Nodular hidradenoma

Cell Type

Clear

189

• “Clear” cells • Often in cords, islands, or pseudoglandular structures • Cells are of renal origin and are surrounded by prominent blood vessels/extravasated erythrocytes

Renal cell carcinoma

190

Cell Type

Clear

• “Clear” cells • Cells are sebocytes often with spiky/scalloped nuclei bordered by several layers of basaloid cells (arrows) • Generally on low power is a downward lobular proliferation from the epidermis

Sebaceous adenoma

Cell Type

Clear

191

• “Clear” cells • Cells are foamy histiocytes (filled with lipid), arranged in between collagen bundles • Often a thin epidermis (eyelid skin) • Vellus hairs may be present (eyelid skin)

Xanthelasma

192

Cell Type

Clear

• “Clear” cells • Cells are histiocytes, arranged in a well-circumscribed mass in the upper dermis • Touton giant cells and eosinophils often seen

Xanthogranuloma (older lesion)

Cell Type

Clear

193

• “Clear” cells • Cells are foamy histiocytes (filled with lipid), in clusters in the dermis • Free lipid is present in eruptive xanthomas

Xanthoma

194

Cell Type

Clear

(a)

(b)

(c)

(d)

(e)

(f)

“Clear cells” a Cryptococcosis, gelatinous: clear spaces representing the capsule of the organism b Granular cell tumor: cells with grainy cytoplasm, small and large

Key differences

c Hibernoma: cells with net-like vaculolated cytoplasm d Leishmaniasis: macrophages filled with organisms e Lepromatous leprosy: histiocytes filled with organisms; linear arrangement on low power f Lipoma: clear adipocytes; peripheral nuclei

Cell Type

(g)

(h)

(i)

(j)

(k)

(l)

“Clear cells” (cont.) g Melanoma, balloon cell: atypical nuclei with clear cytoplasm h Nodular hidradenoma: clear cells with interspersed ducts and hyalinized collagen i Renal cell carcinoma: clear cells with extravasated erythrocytes

Clear

195

(m)

j Sebaceous adenoma: clear sebocytes with star-shaped nuclei with a rim of basaloid cells k Xanthelasma: foamy cells interspersed in eyelid skin l Xanthogranuloma: foamy cells with some Touton cells m Xanthoma, eruptive: foamy cells and extracellular lipid

Key differences

196

Cell Type

Melanocytic

• Melanocytes • Cells are small and spindled/dendritic with cells containing melanin pigment • Dermis often hyalinized • Melanophages often present

Blue nevus

Cell Type

Melanocytic

197

• Melanocytes that are spindled (and also appear rounded when fascicles are cut cross-wise) (so-called biphasic pattern) • Often bulbous into the deep dermis • Scattered melanin pigment within the cells

Blue nevus, cellular

198

Cell Type

Melanocytic

• Melanocytes • Epithelioid melanocytes are admixed with, or bordered by, uniformly distributed melanophages • Pattern on low power is wedge shaped (often centered around a follicle)

Deep penetrating nevus

Cell Type

Melanocytic

199

• Melanocytes • Cells are confluent at the junction with irregularly sized nests, scattered high and low within the epidermis • Atypical cells and mitoses in epidermal and dermal nests

Melanoma

200

Cell Type

Melanocytic

• Melanocytes • Cells are spindled and arranged in bundles infiltrating through collagen • Cells are atypical • Often overlying in situ melanoma changes in epidermis

Melanoma, desmoplastic

Cell Type

Melanocytic

201

• Melanocytes • Pigmented spindle cells are arranged in vertical fascicles in the base of the epidermis • Pushing margin into superficial dermis

Pigmented spindle cell nevus of Reed

202

Cell Type

Melanocytic

• Melanocytes • Cells are in irregularly shaped nests, sometimes confluent, confined to area above a dermal scar • Predominantly junctional involvement

Recurrent nevus

Cell Type

• Melanocytes, spindled and epithelioid • Cells are in vertical fascicles within the epidermis (“school of fish”) • Well circumscribed and symmetric

Melanocytic

203

• Kamino bodies • Clefting may be seen above nests • Cells are atypical but all resemble each other

Spitz nevus

204

Cell Type

Melanocytic

(a)

(b)

(c)

(d)

Melanocytes a Blue nevus: finely pigmented spindle/dendritic cells within the dermis b Deep penetrating nevus: wedge-shaped epithelioid melanocytes admixed with melanophages

Key differences

c Intradermal nevus: circular melanocytes with fine brown pigment in nests (clusters); maturation (cells become smaller) with depth d Melanoma: atypical cells in epidermis and dermis, asymmetric, dermal mitoses

Cell Type

(e)

(f)

(g)

(h)

Melanocytes (cont.) e Melanoma, desmoplastic: atypical spindle cells infiltrating through collagen f Pigmented spindle cell nevus of Reed: vertically arranged pigmented cells in the base of the epidermis with a pushing margin into the dermis

Melanocytic

205

g Recurrent nevus: irregular nests of pigmented cells above a scar h Spitz nevus: vertically arranged epithelioid and spindle cells, symmetric

Key differences

206

• • • •

Cell Type

Spindle

Short spindle cells in a “busy dermis” Epidermis often acanthotic and pigmented Cells entrap collagen at the periphery (arrow) Collagen bundles appear to be “coming at you” (90° to slide surface)

Dermatofibroma

Cell Type

Spindle

207

• Spindle cells filling dermis • Cells are monomorphous and arranged in a storiform (cartwheel) pattern • Infiltration into the fat in layered or honeycomb pattern

Dermatofibrosarcoma protuberans

208

Cell Type

Spindle

• Spindle cells • Cells have round pink cytoplasmic inclusions (arrows) • Cells are arranged in long fascicles

Infantile digital fibromatosis

Cell Type

Spindle

209

• Spindle cells, hyperchromatic • Interspersed erythrocytes • Intracytoplasmic pink globules (erythrophagolysosomes) (arrows)

Kaposi sarcoma, nodular

210

Cell Type

Spindle

• Spindle cells • Cells are arranged in fascicles which intersect at a 90° angle • Cigar-shaped nuclei (arrows)

Leiomyoma

• Cells cut in cross-section have perinuclear vacuoles around round nuclei Note Normal nipple has small bundles of smooth muscle cells (same appearance as an accessory nipple; see page 4)

Cell Type

Spindle

211

• Spindle cells • Cells have thin, wavy nuclei (long arrow), looks like “shredded carrot” • Bubble-gum pink stroma • Scattered mast cells (short arrow) • Not encapsulated

Neurofibroma

212

Cell Type

Spindle

• Spindle cells • Myxoid areas of elongated cells with oval nuclei with tapered ends and elongated cytoplasm (“tissue culture” fibroblasts)

Nodular fasciitis

• • • •

Extravasated erythrocytes Mitoses may be seen Radial arrangement of blood vessels at periphery Deep tumor, often no epidermis present

Cell Type

Spindle

213

• Spindle cells • Cells are arranged in fascicles with characteristic clefting • Often not truly encapsulated

Palisaded encapsulated neuroma

214

Cell Type

Spindle

• Spindle cells • Cells are arranged parallel to epidermis • Vessels oriented perpendicular to epidermal surface

Scar

Cell Type

• • • •

Spindle cells Antoni A areas: cellular Antoni B areas: myxoid Verocay bodies (arrows): palisaded arrangement of nuclei around a central pink area of collagen

Spindle

215

• Encapsulated • Vascular spaces may be very dilated • Often a deep tumor with no epidermis present

Schwannoma

216

Cell Type

Spindle

(a)

(b)

(c)

(d)

(e)

(f)

Spindle cells a Blue nevus, cellular: bulbous projection into deeper dermis, some cells have melanin pigment b Dermatofibroma: collagen entrapment at periphery, epidermal acanthosis c Dermatofibrosarcoma protuberans: monomorphous cells in cartwheel arrangement; infiltration into fat

Key differences

d Infantile digital fibromatosis: bright pink cytoplasmic inclusions e Kaposi sarcoma, nodular: atypical spindle cells with interspersed erythrocytes and intracytoplasmic erythrophagolysosomes f Leiomyoma: cigar-shaped nuclei in long fascicles

Cell Type

(g)

(h)

(i)

(j)

Spindle

217

(k)

Spindle cells (cont.) g Neurofibroma: wavy nuclei, mast cells, bubble-gum pink stroma h Nodular fasciitis: tissue culture fibroblasts, extravasated erythrocytes, often deep in the fat

i Palisaded encapsulated neuroma: clefts between collections of spindle cells with nuclear palisading j Scar: spindle cells arranged parallel to epidermal surface k Schwannoma: Verocay bodies, myxoid areas, encapsulated

Key differences

218

• • • •

Cell Type

Giant

Giant cells with bizarre nuclei Cells are atypical Mitoses Often a grenz zone above the atypical cells and solar elastosis flanking the atypical cells

Atypical fibroxanthoma

Cell Type

Giant

219

• Giant cells of osteoclastic type (nuclei arranged haphazardly on one side of the cell) • Nuclei of giant cells resemble the nuclei of adjacent histiocytes • Hemosiderophages • Often a deep tumor (no epidermis present)

Giant cell tumor of tendon sheath

220

Cell Type

Giant

• Touton giant cells (wreath of nuclei with pink center and foamy cytoplasm outside the wreath) arranged at the periphery of the collection of histiocytes • Eosinophils may be present • Scattered foamy cells may be present

Juvenile xanthogranuloma

Cell Type

Giant

221

• Oncocytic giant cells (multinucleated cells with groundglass pink cytoplasm) (arrow)

Reticulohistiocytosis

222

Cell Type

Giant

• Foreign-body giant cells (haphazardly arranged nuclei), neutrophils • Keratin spicules can be seen near/engulfed by multinucleated cells

Ruptured cyst/keratin granuloma

Cell Type

Giant

223

• Langhans giant cells (nuclei arranged in a horseshoe shape) (arrow) • Epidermis usually normal • Giant cells within collections of histiocytes that are usually “naked” (lacking surrounding lymphocytes)

Sarcoidosis

224

Cell Type

Giant

• Foreign-body giant cells • Cells surrounding suture material (braided in this case)

Suture granuloma

Cell Type

(a)

(b)

(c)

(d)

(e)

(f)

Giant cells a Atypical fibroxanthoma: atypical nuclei, mitoses b Giant cell tumor of tendon sheath: osteoclastic giant cells c Juvenile xanthogranuloma: Touton giant cells d Reticulohistiocytosis: oncocytic giant cells e Ruptured cyst/keratin granuloma: foreign-body giant cells, keratin spicules

Giant

225

(g)

f Sarcoidosis: Langhans giant cells, naked granulomas g Suture granuloma: foreign-body giant cells, suture material Note Infections and scars are other common entities that frequently have giant cells Note This list is of the classical type of giant cell for each entity; none of the giant cells are pathognomonic

Key differences



4

Color—Blue • Blue tumor, 229 • Blue infiltrate, 238 • Mucin and glands or ducts, 246 • Mucin, 250


Color—Blue

• • • • •

Blue tumor

229

Blue tumor Peripheral palisading Retraction of stroma around individual islands Stroma often mucinous Islands may contain mitoses and necrotic cells

Basal cell carcinoma

230

Color—Blue

Blue tumor

• Blue tumor • Tumor composed of cells with monomorphous, centrally located, round nuclei (arrows) • Cells surround vascular spaces

Glomus tumor

Color—Blue

• • • • •

Blue tumor

231

Blue tumor Trabecular or nodular pattern on low power Tumor composed of cells with pale nuclei on high power Nuclei have a “salt and pepper” look Numerous scattered mitoses and necrotic cells

Merkel cell carcinoma

232

Color—Blue

Blue tumor

• Blue tumor • Scattered sebocytes among smaller, blue cells

Sebaceoma (sebaceous epithelioma)

Color—Blue

• Blue tumor • “Blue balls” in the dermis • Islands of tumor may be peppered by lymphocytes and hyaline pink droplets

Blue tumor

233

• Tumor composed of more peripheral blue cells and more central pale/clear cells that may be arranged in a trabeculated pattern • Occasional ductal components

Spiradenoma

234

Color—Blue

• • • •

Blue tumor

Blue tumor Peripheral palisading Generally no epidermal connection Well circumscribed with clefts between the tumor as a whole and the normal dermis • Papillary mesenchymal bodies may be seen

Trichoblastoma

Color—Blue

• Blue tumor • Often an epidermal connection • Grape-like fronds of cells or reticulated islands of basaloid cells with peripheral palisading

Blue tumor

235

• Fibrotic stroma • Clefting between the fibrotic stroma and bordering normal dermis • Papillary mesenchymal bodies may be seen

Trichoepithelioma

236

Color—Blue

Blue tumor

• Blue tumor • Groups of cells in the dermis (cannon balls) forming small vascular spaces with erythrocytes • Clefts may be seen around the groups of cells

Tufted angioma

Color—Blue

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

Blue tumors a Basal cell carcinoma: peripheral palisading, clefts between blue islands and stroma b Glomus tumor: round monomorphous cells c Merkel cell carcinoma: pale salt and pepper nuclei d Sebaceoma (sebaceous epithelioma): blue cells with occasional interspersed sebocytes e Spiradenoma: two cell types – pale and blue

Blue tumor

237

f Trichoblastoma: peripheral palisading, papillary mesenchymal bodies g Trichoepithelioma: grape-like fronds of cells with peripheral palisading, fibrotic stroma h Tufted angioma: “cannonballs” of blue cells forming vascular spaces Note Some pathologists consider trichoepithelioma to be a variant of trichoblastoma

Key differences

238

Color—Blue

Blue infiltrate

• Blue dense infiltrate • Lymphoplasmacytic infiltrate surrounds and destroys hair follicles • Free hair shafts may be seen in the dermis • Scarring

Acne keloidalis

Color—Blue

Blue infiltrate

239

• Blue dense infiltrate • Grenz zone • Infiltrate composed of lymphocytes, histiocytes, eosinophils, neutrophils • Variable presence of vasculitis

Granuloma faciale

240

Color—Blue

Blue infiltrate

• Blue dense infiltrate • Infiltrate is perivascular and infiltrating through collagen • Cells are atypical with slightly granular cytoplasm (arrows)

Leukemia (myelogenous)

Color—Blue

Blue infiltrate

241

• Blue dense infiltrate • Infiltrate composed of monomorphous lymphocytes • Often a “bottom-heavy” infiltrate Note Clinical history and special stains may be critical in making the diagnosis

Lymphoma

242

Color—Blue

Blue infiltrate

• Blue dense infiltrate • Infiltrate composed of mast cells (arrows) with “fried egg” appearance (round nucleus, granular cytoplasm)

Mastocytoma

Color—Blue

• • • •

Blue infiltrate

243

Blue dense infiltrate Papillary dermal edema Infiltrate composed of neutrophils Generally vasculitis is not prominent

Sweet syndrome

244

Color—Blue

Blue infiltrate

(a)

(b)

(c)

(d)

Blue dense infiltrate a Acne keloidalis: lymphoplasmacytic infiltrate around/ destroying hair follicles with scarring b Discoid lupus erythematosus: interface changes, superficial and deep perivascular and periadnexal lymphocytic infiltrate, pigment incontinence

Key differences

c Granuloma faciale: mixed infiltrate with eosinophils under a grenz zone, vasculitis d Leukemia (myelogenous): atypical cells with granular cytoplasm around vessels and infiltrating dermis

Color—Blue

(e)

Blue infiltrate

245

(f)

(g)

Blue dense infiltrate (cont.) e Lymphoma: monomorphous lymphocytes filling dermis f Mastocytoma: dense collection of mast cells with “fried egg” appearance g Sweet syndrome: infiltrate of neutrophils Note Infections may also have a dense infiltrate

Key differences

246

Color—Blue

Mucin and glands or ducts

• Bluish-pink chondroid areas (long arrows) and duct-like spaces (short arrows) • Well circumscribed

Chondroid syringoma

Color—Blue


247

• Mucin in pools dissecting collagen bundles • In center of pools, there are epithelial islands with variable ductal differentiation

Mucinous carcinoma

248

Color—Blue


• Mucin • Mucin often surrounded by giant cells • May see mucosal epithelium and/or minor salivary glands

Mucocele

Color—Blue

(a)


249

(b)

(c)

Mucin and glands or ducts a Chondroid syringoma: well-circumscribed blue-pink cartilaginous area containing duct-like spaces b Mucinous carcinoma: pools of mucin containing epithelial islands c Mucocele: pool of mucin with surrounding fibrosis/ inflammation; adjacent salivary glands

Key differences

250

Color—Blue

Mucin

• Well-circumscribed mucin (blue, lacy appearance) • Acral skin • Not a true cyst (no epithelial lining)

Digital mucous cyst

Color—Blue

Mucin

251

• Well-circumscribed mucin • Non-acral location

Focal cutaneous mucinosis

252

Color—Blue

Mucin

• Mucin within a distorted hair follicle

Follicular mucinosis

Color—Blue

Mucin

253

• Mucin between collagen bundles • Perivascular lymphocytes

Lupus tumidus

254

Color—Blue

Mucin

• Variable mucin in nodular collections with spindle cells • Nodules separated by fibrosis Note Lesions with abundant mucin are probably best termed nerve sheath myxomas

Neurothekeoma

Color—Blue

Mucin

255

• Mucin filling the dermis (spares papillary dermis)

Pretibial myxedema

256

Color—Blue

Mucin

(a)

(b)

(c)

(d)

(e)

(f)

Mucin a Digital mucous cyst: acral location b Focal cutaneous mucinosis: non-acral location c Follicular mucinosis: mucin within follicle d Neurothekeoma: lobules of spindle or epithelioid cells in variable myxoid background

Key differences

e Nodular fasciitis: elongated “tissue culture” cells in myxoid background f Pretibial myxedema: mucin filling reticular dermis


5

Color—Pink • Pink material, 259 • Pink dermis with vessels, 265 • Epidermal necrosis, 268


Color—Pink

Pink material

259

• Amorphous pink material in upper dermis • Plasma cells

Amyloid

260

Color—Pink

Pink material

• Pink material in the dermis with clefting (later lesions) • Late stage has neutrophils interspersed with prominent fibrosis and “cholesterol clefts” • Palisading of neutrophils and nuclear dust around altered collagen (earlier lesions) • Swollen vessel walls and fibrin deposits (earlier lesions)

Erythema elevatum diutinum (extracellular cholesterolosis)

Color—Pink

Pink material

261

• Pink material with shadows of nuclei within, may have a “butterscotch” color • Basaloid cells • Calcification may be present • Giant cells often seen

Pilomatricoma

262

Color—Pink

Pink material

• Pink material that is dense keratin • Stratified squamous epithelium with no granular layer (tricholemmal differentiation)

Proliferating pilar tumor

Color—Pink

Pink material

263

• Pink material arranged in a fenestrated or clefted fashion • Hyalinized, relatively acellular collagen

Sclerotic fibroma

264

Color—Pink

Pink material

(a)

(b)

(c)

(d)

(e)

Pink material a Amyloid: amorphous pink material, plasma cells b Erythema elevatum diutinum (late stage): fibrosis with clefting and interspersed neutrophils c Pilomatricoma: shadow cells, basaloid cells

Key differences

d Proliferating pilar tumor: dense pink keratin, no granular layer between keratin and epithelium e Sclerotic fibroma: clefts between strands of sclerotic collagen

Color—Pink

Pink dermis with vessels

265

• Pink hyalinized dermis beneath vacuolated basal layer • Lichenoid infiltrate below hyalinized dermis

Lichen sclerosus et atrophicus

266

Color—Pink


• Pink dermis • Atypical, bizarre fibroblasts within dermis • Dilated vessels with plump endothelial cells

Radiation dermatitis

Color—Pink


267

(a)

(b)

Pink dermis with vessels a Lichen sclerosus et atrophicus: pink band of dermis with inflammation below it b Radiation dermatitis: pink dermis with dilated vessels; atypical fibroblasts on higher power

Key differences

268

Color—Pink

Epidermal necrosis

• Epidermal and dermal necrosis • Vessels necrotic with extravasated erythrocytes and visible fungal hyphae that are septate and branching

Aspergillosis

Color—Pink

Epidermal necrosis

269

• Epidermal necrosis with variable dermal change • Reversal of epidermal staining (more basophilic superficially than deep) • Acute lesions are non-inflammatory

Burn

270

Color—Pink

Epidermal necrosis

• Epidermal necrosis (linear, often primarily affecting basal layer) below basket-weave stratum corneum in early lesions

Erythema multiforme

Color—Pink

Epidermal necrosis

271

• Epidermal necrosis with acantholytic cells and multinucleated cells • Follicular necrosis is a clue

Herpes simplex infection

272

Color—Pink

Epidermal necrosis

• Epidermal necrosis or pallor underlying parakeratosis • Basal layer relatively normal

Nutritional deficiency

Color—Pink

Epidermal necrosis

273

(c)

(a)

(d)

(b)

Epidermal necrosis a Aspergillosis: epidermal and dermal necrosis with fungi in areas of destroyed vessels b Burn: epidermal necrosis, sharp demarcation c Erythema multiforme: basket-weave stratum corneum, linear basal cell necrosis

(e)

d Herpes simplex infection: acantholysis and multinucleated cells with rimmed chromatin e Nutritional deficiency: parakeratosis above epidermal necrosis, basal layer often unaffected Note Pityriasis lichenoides et varioliformis acuta may show epidermal necrosis

Key differences


275

Index by Pattern

Polypoid Accessory digit, 3, 7 Accessory nipple, 4, 7 Accessory tragus, 5, 7 Acquired digital fibrokeratoma, 6, 7 Fibroepithelial polyp (not pictured) Fibrous papule, 73, 79 Intradermal nevus, 151, 152, 204 Neurofibroma, 211, 217 Nevus lipomatosus (not pictured) Pyogenic granuloma, 75, 79 Umbilical polyp (not pictured)

Square/rectangular Chronic radiation dermatitis, 266, 267 Keloid (not pictured) Lichen myxedematosus (not pictured) Morphea, 8, 13 Necrobiosis lipoidica, 9, 13, 40 Nephrogenic systemic fibrosis (not pictured) Normal back, 10, 13 Scleredema, 11, 13 Scleromyxedema, 12, 13

Regular epidermal acanthosis Bowen disease, 14, 17 Clear cell acanthoma, 15, 17 Inflammatory linear verrucous epidermal nevus, 91, 96 Normal elbow (not pictured) Psoriasis, 16, 17, 97 Verruciform xanthoma (not pictured)

Pseudoepitheliomatous hyperplasia above abscesses Atypical mycobacterial infection (not pictured) Blastomycosis, 18, 21 Chromomycosis, 19, 21 Coccidioidomycosis, 20, 21

Halogenoderma/bromoderma (not pictured) Keratoacanthoma (not pictured) Paracoccidioidomycosis (not pictured) Pyoderma gangrenosum (not pictured) Sporotrichosis (not pictured) Tuberculosis verrucosa cutis (not pictured)

Proliferation downward from epidermis Fibroepithelioma of Pinkus, 22, 30 Fibrofolliculoma, 23, 30 Inverted follicular keratosis, 24, 30 Nevus sebaceus, 25, 30 Poroma, 26, 31 Sebaceoma (sebaceous epithelioma), 232, 237 Sebaceous adenoma, 190, 195 Seborrheic keratosis, reticulated, 27, 31 Syringofibroadenoma (not pictured) Trichilemmoma, 28, 31 Tumor of the follicular infundibulum, 29, 31

Central pore Dilated pore of Winer, 32, 35 Pilar sheath acanthoma, 33, 35 Sebaceous hyperplasia (not pictured) Trichofolliculoma, 34, 35

Epidermal perforation Calcinosis cutis, perforating, 54, 157, 166 Chondrodermatitis nodularis helicis, perforating (not pictured) Elastosis perforans serpiginosa, 52, 54 Granuloma annulare, perforating (not pictured) Pseudoxanthoma elasticum, perforating (not pictured) Reactive perforating collagenosis, 53, 54

Palisading reactions Churg–Strauss (not pictured) Gout, 36, 40 Granuloma annulare, 37, 40, 135, 155


276

Index by Pattern

Interstitial granulomatous dermatitis (not pictured) Necrobiosis lipoidica, 9, 13, 40 Necrobiotic xanthogranuloma, 38, 40 Rheumatoid nodule, 39, 40 Wegener granulomatosis (not pictured)

Kaposi sarcoma, 74, 79, 155, 209, 216 Lymphangioma, 127, 130 Pyogenic granuloma, 75, 79 Stasis dermatitis, 76, 79 Targetoid hemosiderotic (hobnail) hemangioma, 77, 79 Tufted angioma, 236, 237

Space with a lining Apocrine hidrocystoma, 41, 50 Auricular pseudocyst, 42, 50 Branchial cleft cyst, 43, 50 Bronchogenic cyst (not pictured) Cutaneous ciliated cyst, 44, 50 Cutaneous endometriosis, 45, 50 Dermoid cyst, 46, 51 Epidermal inclusion cyst, 47, 51 Glomangioma (glomuvenous malformation), 51 Median raphe cyst (not pictured) Pilar cyst, 48, 51 Steatocystoma, 49, 51 Thyroglossal duct cyst (not pictured) Venous lake (not pictured)

Cords and tubules Desmoplastic trichoepithelioma, 55, 60 Metastatic breast carcinoma, 56, 60 Microcystic adnexal carcinoma, 57, 60 Morpheaform basal carcinoma, 58, 60 Syringoma, 59, 60

Hyperkeratosis/parakeratosis Actinic keratosis, 93, 96 Axillary granular parakeratosis, 94, 97 Bowen disease, 14, 17 Chondrodermatitis nodularis helicis, 72, 78 Dermatophytosis, 95, 97 Discoid lupus erythematosus, 87, 96, 244 Epidermolytic hyperkeratosis, 100, 106 Flegel disease, 88, 96 Ichthyosis vulgaris (not pictured) Inflammatory linear verrucous epidermal nevus, 91, 96 Lichen planus, 144, 147 Lichen sclerosus et atrophicus, 89, 96, 265, 267 Nutritional deficiency, 97, 272, 273 Papulosquamous diseases (not all are pictured), 16, 17, 91, 92, 96, 97 Pityriasis lichenoides et varioliformis acuta, 146, 147 Pityriasis rubra pilaris, 92, 97 Porokeratosis, 90 Spongiotic diseases (not all are pictured), 76, 79, 118, 119, 123, 134, 135 Tinea versicolor (not pictured)

Papillated dermal tumor Aggressive digital papillary adenocarcinoma, 61, 67 Florid papillomatosis (erosive adenomatosis) of the nipple (nipple adenoma), 62, 67 Hidradenoma papilliferum, 63, 67 Papillary eccrine adenoma, 64, 67 Syringocystadenoma papilliferum, 65, 67 Tubular apocrine adenoma, 66, 67

Circular dermal islands Adenoid cystic carcinoma, 80, 83 Cylindroma, 81, 83 Trichoadenoma, 82, 83 Trichoblastoma, 234, 237 Spiradenoma, 233, 237

(Suggestion of) vessels Angiokeratoma, 124, 130 Angioleiomyoma, 68, 78 Angiolymphoid hyperplasia with eosinophilia, 69, 78 Angiosarcoma, 70, 78 Bacillary angiomatosis, 71, 78 Chondrodermatitis nodularis helicis, 72, 78 Fibrous papule, 73, 79 Glomus tumor/glomangioma, 51, 230, 237

Upper epidermal change Bowen disease, 14, 17 Clonal seborrheic keratosis, 98, 106 Epidermodysplasia verruciformis, 99, 106 Epidermolytic hyperkeratosis, 100, 106 Myrmecium, 101, 107 Orf, 102, 107 Paget disease, 103, 107 Verruca plana, 104, 107 Verruca vulgaris, 105, 107

Acantholysis Acantholytic acanthoma (not pictured) Acantholytic dyskeratotic acanthoma (not pictured) Actinic keratosis (not pictured) Darier disease, 108, 116 Grover disease, 109, 116 Hailey–Hailey disease, 106, 110, 116 Herpes virus infection, 111, 116, 271, 273 Pemphigus foliaceus, 112, 117 Pemphigus vulgaris, 113, 117 Pityriasis rubra pilaris, 92, 97 Squamous cell carcinoma, 114, 117 Warty dyskeratoma, 115, 117

Index by Pattern

Eosinophilic spongiosis Allergic contact dermatitis, 118, 123 Arthropod bite reaction, 119, 123 Bullous pemphigoid, 123, 125, 130 Incontinentia pigmenti, 120, 123 Pemphigoid gestationis, 125 Pemphigus vegetans, 121, 123 Pemphigus vulgaris, 113, 117 Scabies, 122, 123

Subepidermal space Angiokeratoma, 124, 130 Bullous pemphigoid, 123, 125, 130 Dermatitis herpetiformis, 126, 130 Erythema multiforme, 270, 273 Herpes gestationis, 125 Lymphangioma, 127, 130 Phototoxic reactions (not pictured) Polymorphous light eruption, 128, 130 Porphyria cutanea tarda, 129, 130 Pseudoporphyria (not pictured) Suction blister (not pictured) Sweet syndrome, 243, 245

Perivascular infiltrate Erythema annulare centrifugum (not pictured) Guttate psoriasis (not pictured) Gyrate erythema, 131, 135 Leukocytoclastic vasculitis, 132, 135 Lymphocytic angiitis (not pictured) Pigmented purpuric dermatosis, 133, 135 Pityriasis rosea, 134, 135

Band-like upper dermal infiltrate Fixed drug reaction, 141, 147 Langerhans cell histiocytosis, 136, 140 Lichen planus, 144, 147 Mastocytosis, 137, 140, 242, 245 Mycosis fungoides, 138, 140 Zoon balanitis, 139, 140 See also Interface reaction, 141–7

Interface reaction Benign lichenoid keratosis (not pictured) Discoid lupus erythematosus, 87, 96, 244 Erythema multiforme, 270, 273 Fixed drug reaction, 141, 147 Graft-versus-host disease, 142, 147 Halo nevus (not pictured) Lichen nitidus, 143, 147 Lichen planus, 144, 147 Lichen sclerosus et atrophicus, 89, 96, 265, 267 Lichen striatus, 145, 147 Pigmented purpuric dermatosis, 133, 135

277

Pityriasis lichenoides et varioliformis acuta, 146, 147 Porokeratosis, 90 Regressed melanoma (not pictured) Secondary syphilis (not pictured) Some neoplasms (not pictured)

Granular “material” in cells Aluminum chloride (Drysol solution), 148, 152 Ferric subsulfate (Monsel solution), 149, 152 Granular cell tumor, 182, 194 Hemosiderin, 45, 76, 77, 79, 150, 152 Leishmaniasis, 152, 184, 194 Melanin, 151, 152, 153, 155, 196, 197, 216 Other tumors with granular cell change (e.g. basal cell carcinoma, dermatofibroma, fibrous papule) (not pictured) Tattoo, 152, 165, 167

Dermal material Amyloidosis, nodular, 156, 166 Calcinosis cutis, 54, 157, 166 Erythropoietic protoporphyria, 158, 166 Gel foam, 159, 166 Gout, 36, 40 Lipoid proteinosis, 160, 166 Ochronosis, 161, 167 Osteoma cutis, 162, 167 Paraffinoma, 163, 167 Pseudoxanthoma elasticum, 164, 167 Tattoo, 152, 165, 167 See also Blue mucin, 250–6, and Pink material, 259–64

“Busy” dermis Blue nevus, hypopigmented, 153, 155 Dermatofibroma, 155, 206, 216 Granuloma annulare, 37, 40, 54, 135, 155 Kaposi sarcoma, 74, 79, 155, 209, 216 Leukemia cutis, 155, 240, 244 Metastatic breast carcinoma, interstitial pattern (carcinoma en cuirasse), 154, 155

Change in the fat Dermatofibrosarcoma protuberans (often extends into the fat), 207, 216 Erythema induratum, 168, 177 Erythema nodosum, 169, 176 Hibernoma, 183, 194 Lipodermatosclerosis, 170, 176 Lipoma/angiolipoma, 176, 186, 194 Lupus profundus, 171, 177 Nodular fasciitis (often deep in the fat), 212, 217, 256 Other adipose tumors (not pictured) Other panniculitides (not pictured) Pancreatic fat necrosis, 172, 177 Polyarteritis nodosa, 173, 176

278

Index by Pattern

Post-steroid panniculitis, 174 Sclerema neonatorum (not pictured) Subcutaneous fat necrosis of the newborn, 174, 177 Subcutaneous T-cell lymphoma, 175, 176

“Clear cells” Clear cell acanthoma, 15, 17 Cryptococcosis, gelatinous, 181, 194 Granular cell tumor, 182, 194 Hibernoma, 183, 194 Leishmaniasis, 152, 184, 194 Lepromatous leprosy, 185, 194 Lipoma/angiolipoma, 176, 186, 194 Melanoma, balloon cell, 187, 195 Nodular hidradenoma, 188, 195 Other clear cell neoplasms (e.g. clear cell basal cell carcinoma) (not pictured) Renal cell carcinoma, 189, 195 Sebaceous adenoma, 190, 195 Trichilemmoma, 28, 31 Xanthelasma, 191, 195 Xanthogranuloma, 192, 195, 220, 225 Xanthoma, 193, 195

Melanocytes Blue nevus, 196, 204 Cellular blue nevus, 197, 216 Deep penetrating nevus, 198, 204 Intradermal nevus, 151, 152, 204 Melanoma, 199, 204 Melanoma, desmoplastic, 200, 205 Other melanocytic tumors/proliferations (not pictured) Pigmented spindle cell nevus of Reed, 201, 205 Recurrent nevus, 202, 205 Spitz nevus, 203, 205

Spindle cells Atypical fibroxanthoma, 218, 225 Blue nevus, cellular, 197, 216 Dermatofibroma, 155, 206, 216 Dermatofibrosarcoma protuberans, 207, 216 Fibrous papule, 73, 79 Infantile digital fibromatosis, 208, 216 Kaposi sarcoma, nodular, 209, 216 Leiomyoma, 210, 216 Neurofibroma, 211, 217 Neurothekeoma, 254, 256 Nodular fasciitis, 212, 217, 256 Other fibrous tumors (not pictured) Other neural tumors (not pictured) Other smooth muscle tumors (not pictured) Palisaded encapsulated neuroma, 213, 217 Scar, 214, 217 Schwannoma, 215, 217 Squamous cell carcinoma (not pictured)

Giant cells Atypical fibroxanthoma, 218, 225 Erythema nodosum, 169, 176 Giant cell tumor of tendon sheath, 219, 225 Infections (not pictured) Juvenile xanthogranuloma, 192, 195, 220, 225 Mucocele, 248, 249 Necrobiosis lipoidica, 9, 13, 40 Necrobiotic xanthogranuloma, 38, 40 Pilomatricoma, 261, 264 Reticulohistiocytosis, 221, 225 Ruptured cyst/keratin granuloma, 222, 225 Sarcoidosis, 223, 225 Scar (not pictured) Suture granuloma, 224, 225

Blue tumor Basal cell carcinoma, 229, 237 Glomus tumor, 230, 237 Lymphoma, 241, 245 Merkel cell carcinoma, 231, 237 Sebaceoma (sebaceous epithelioma), 232, 237 Spiradenoma, 233, 237 Trichoblastoma, 234, 237 Trichoepithelioma, 235, 237 Tufted angioma, 236, 237

Blue dense infiltrate Acne keloidalis, 238, 244 Discoid lupus erythematosus, 87, 96, 244 Granuloma faciale, 239, 244 Infections (not pictured) Leukemia, 240, 244 Lymphoma, 241, 245 Mastocytoma, 137, 140, 242, 245 Myeloma (not pictured) Sweet syndrome, 243, 245

Mucin and glands or ducts Chondroid syringoma, 246, 249 Mucinous carcinoma, 247, 249 Mucocele, 248, 249

Mucin Digital mucous cyst, 250, 256 Focal cutaneous mucinosis, 251, 256 Follicular mucinosis, 252, 256 Lichen myxedematosus (not pictured) Lupus tumidus, 253 Neurothekeoma, 254, 256 Nodular fasciitis, 212, 217, 256 Pretibial myxedema, 255, 256 Reticular erythematous mucinosis (not pictured) Scleromyxedema, 12, 13

Index by Pattern

Pink material Amyloid, 156, 166, 259, 264 Colloid milium (not pictured) Erythema elevatum diutinum, 260, 264 Erythropoietic protoporphyria, 158, 166 Gout, 36, 40 Lichen sclerosus et atrophicus, 89, 96, 265, 267 Lipoid proteinosis, 160, 166 Pilomatricoma, 261, 264 Proliferating pilar tumor, 262, 264 Rheumatoid nodule, 39, 40 Sclerotic fibroma, 263, 264

Erythema multiforme, 270, 273 Herpes simplex infection, 271, 273 Nutritional deficiency, 97, 272, 273 Pressure necrolysis (not pictured)

“Normal” skin on low power

Epidermal necrosis

Anetoderma (not pictured) Argyria (not pictured) Connective tissue nevus (not pictured) Dermatophyte/tinea versicolor* (not pictured) Erythema dyschromicum perstans* (not pictured) Ichthyosis vulgaris (not pictured) Macular amyloidosis* (not pictured) Scleredema, 11, 13 Telangiectasia macularis eruptiva perstans (not pictured) Urticaria (not pictured) Vitiligo (not pictured)

Aspergillosis, 268, 273 Burn, 269, 273

*When subtle.

Pink dermis with vessels Lichen sclerosus et atrophicus, 89, 96, 265, 267 Radiation dermatitis, 266, 267

279

280

Index by Histological Category

Acantholytic disorders Darier disease, 108, 116 Grover disease, 109, 116 Hailey–Hailey disease, 110, 116 Herpes virus infection, 111, 116, 271, 273 Pemphigus foliaceus, 112, 117 Pemphigus vegetans, 121, 123 Pemphigus vulgaris, 113, 117 Squamous cell carcinoma, acantholytic, 114, 117 Warty dyskeratoma, 115, 117

Benign tumors Adipose tumors Hibernoma, 183, 194 Lipoma/angiolipoma, 176, 186, 194

Adnexal tumors Follicular Desmoplastic trichoepithelioma, 55, 60 Fibroepithelioma of Pinkus, 22, 30 Fibrofolliculoma, 23, 30 Pilar sheath acanthoma, 33, 35 Pilomatricoma, 261, 264 Trichilemmoma, 28, 31 Trichoadenoma, 82, 83 Trichoblastoma, 234, 237 Trichoepithelioma, 235, 237 Trichofolliculoma, 34, 35 Tumor of the follicular infundibulum, 29, 31

Syringoma, 59, 60 Tubular apocrine adenoma, 66, 67 Sebaceous Nevus sebaceus of Jadassohn, 25, 30 Sebaceoma/sebaceous epithelioma, 232, 237 Sebaceous adenoma, 190, 195

Fibrous tumors Dermatofibroma, 155, 206, 216 Dermatofibrosarcoma protuberans, 207, 216 Digital fibrokeratoma, 6, 7 Fibrous papule, 73, 79 Giant cell tumor of tendon sheath, 219, 225 Infantile digital fibromatosis, 208, 216 Nodular fasciitis, 212, 217, 256 Scar, 214, 217 Sclerotic fibroma, 263, 264

Melanocytic tumors Blue nevus, 196, 204 Blue nevus, hypopigmented, 153, 155 Cellular blue nevus, 197, 216 Deep penetrating nevus, 198, 204 Intradermal nevus, 151, 152, 204 Pigmented spindle cell nevus of Reed, 201, 205 Recurrent nevus, 202, 205 Spitz nevus, 203, 205

Miscellaneous tumors Glandular (apocrine and eccrine) Apocrine hidrocystoma, 41, 50 Chondroid syringoma, 246, 249 Cylindroma, 81, 83 Hidradenoma papilliferum, 63, 67 Papillary eccrine adenoma, 64, 67 Poroma, 26, 31 Spiradenoma, 233, 237 Syringocystadenoma papilliferum, 65, 67

Bronchogenic cyst (not pictured) Clear cell acanthoma, 15, 17 Cutaneous ciliated cyst, 44, 50 Dilated pore of Winer, 32, 35 Epidermal inclusion cyst, 47, 51 Florid papillomatosis (erosive adenomatosis) of the nipple, 62, 67 Granular cell tumor, 182, 194 Inverted follicular keratosis, 24, 30


Index by Histological Category Mastocytoma, 137, 140, 242, 245 Nipple adenoma, 62, 67 Pilar cyst, 48, 51 Seborrheic keratosis, clonal type, 98, 106 Seborrheic keratosis, reticulated, 27, 31 Steatocystoma, 49, 51 Venous lake (not pictured)

Neural tumors Accessory digit, 3, 7 Neurofibroma, 211, 217 Neurothekeoma, 254, 256 Palisaded encapsulated neuroma, 213, 217 Schwannoma, 215, 217

Smooth muscle tumors Accessory nipple, 4, 7 Angioleiomyoma, 68, 78 Leiomyoma, 210, 216

Vascular tumors Angiokeratoma, 124, 130 Angiolymphoid hyperplasia with eosinophilia, 69, 78 Glomus tumor, 230, 237 Lymphangioma, 127, 130 Pyogenic granuloma, 75, 79 Targetoid hemosiderotic (hobnail) hemangioma, 77, 79 Tufted angioma, 236, 237

Connective tissue disorders Discoid lupus erythematosus, 87, 96, 244 Lichen sclerosus et atrophicus, 89, 96, 265, 267 Lupus profundus, 171, 177 Lupus tumidus, 253 Morphea, 8, 13 Polyarteritis nodosa, 173, 176 Rheumatoid nodule, 39, 40 Scleredema, 11, 13 Scleromyxedema, 12, 13

Depositions Endogenous material Amyloidosis, 156, 166, 259, 264 Calcinosis cutis, 54, 157, 166 Digital mucous cyst, 250, 256 Erythropoietic protoporphyria, 158, 166 Focal cutaneous mucinosis, 251, 256 Follicular mucinosis, 252, 256 Gout, 36, 40 Hemosiderin, 45, 76, 77, 79, 150, 152 Lipoid proteinosis, 160, 166 Melanin, 151, 152, 153, 155, 196, 197, 216 Mucocele, 248, 249 Osteoma cutis, 162, 167

Pretibial myxedema, 255, 256 Pseudoxanthoma elasticum, 164, 167

Foreign material Aluminum chloride (Drysol) , 148, 152 Ferric subsulfate (Monsel solution) , 149, 152 Gel foam, 159, 166 Ochronosis, 161, 167 Paraffinoma, 163, 167 Tattoo, 152, 165, 167

Genodermatoses Epidermolytic hyperkeratosis, 100, 106 Erythropoietic protoporphyria, 158, 166 Incontinentia pigmenti, 120, 123 Lipoid proteinosis, 160, 166

Granulomatous Granuloma annulare, 37, 40, 135, 155 Necrobiosis lipoidica, 9, 13, 40 Necrobiotic xanthogranuloma, 38, 40 Rheumatoid nodule, 39, 40 Ruptured cyst/keratin granuloma, 222, 225 Sarcoidosis, 223, 225 Suture granuloma, 224, 225

Histiocytic Langerhans cell histiocytosis, 136, 140 Reticulohistiocytosis, 221, 225 Xanthelasma, 191, 195 Xanthogranuloma, 192, 195, 220, 225 Xanthoma, 193, 195

Infections Aspergillosis, 268, 273 Bacillary angiomatosis, 71, 78 Blastomycosis, 18, 21 Chromomycosis, 19, 21 Coccidioidomycosis, 20, 21 Cryptococcosis, 181, 194 Dermatophytosis, 95, 97 Epidermodysplasia verruciformis, 99, 106 Kaposi sarcoma, 74, 79, 155, 209, 216 Leishmaniasis, 152, 184, 194 Lepromatous leprosy, 185, 194 Myrmecium, 101, 107 Orf, 102, 107 Verruca plana, 104 Verruca vulgaris, 105

Inflammatory disorders Blistering disorders Bullous pemphigoid, 123, 125, 130 Dermatitis herpetiformis, 126, 130

281

282

Index by Histological Category

Herpes gestationis, 125 Porphyria cutanea tarda, 129, 130

Interface reactions Discoid lupus erythematosus, 87, 96, 244 Erythema multiforme, 270, 273 Fixed drug reaction, 141, 147 Graft-versus-host disease, 142, 147 Lichen nitidus, 143, 147 Lichen planus, 144, 147 Lichen striatus, 145, 147 Pigmented purpuric dermatosis, 133, 135 Pityriasis lichenoides et varioliformis acuta, 146, 147 Porokeratosis, 90

Miscellaneous Acne keloidalis, 238, 244 Axillary granular parakeratosis, 94, 97 Burn, 269, 273 Chondrodermatitis nodularis helicis, 72, 78 Elastosis perforans serpiginosa, 52, 54 Erythema annulare centrifugum (not pictured) Erythema elevatum diutinum, 260, 264 Flegel disease, 88, 96 Granuloma faciale, 239, 244 Mastocytosis, 137, 140, 242, 245 Nutritional deficiency, 97, 272, 273 Pigmented purpuric dermatosis, 133, 135 Polymorphous light eruption, 128, 130 Porokeratosis, 90 Radiation dermatitis, 266, 267 Reactive perforating collagenosis, 53, 54 Scabies, 122, 123 Sweet syndrome, 243, 245 Zoon balanitis, 139, 140

Spongiotic disorders Arthropod bite reaction, 119, 123 Eosinophilic spongiosis, 118–123 Pityriasis rosea, 134, 135 Stasis dermatitis, 76, 79

Vasculitis Erythema induratum, 168, 177 Granuloma faciale, 239, 244 Leukocytoclastic vasculitis, 132, 135 Polyarteritis nodosa, 173, 176

Malformations Accessory digit, 3, 7 Accessory nipple, 4, 7 Accessory tragus, 5, 7 Auricular pseudocyst, 42, 50 Branchial cleft cyst, 43, 50 Cutaneous endometriosis, 45, 50 Dermoid cyst, 46, 51

Malignant tumors Carcinomas Adenoid cystic carcinoma, 80, 83 Aggressive digital papillary adenocarcinoma, 61, 67 Basal cell carcinoma, 229, 237 Basal cell carcinoma, morpheaform, 58, 60 Bowen disease, 14, 17 Merkel cell carcinoma, 231, 237 Metastatic breast carcinoma, 56, 60, 154, 155 Microcystic adnexal carcinoma, 57, 60 Mucinous carcinoma, 247, 249 Paget disease, 103, 107 Proliferating pilar tumor, 262, 264

Melanocytic tumors Panniculitis and other disorders of adipose tissue Erythema induratum, 168, 177 Erythema nodosum, 169, 176 Lipodermatosclerosis, 170, 176 Lupus profundus, 171, 177 Pancreatic fat necrosis, 172, 177 Polyarteritis nodosa, 173, 176 Subcutaneous fat necrosis of the newborn, 174, 177 Subcutaneous T-cell lymphoma, 175, 176

Papulosquamous disorders Inflammatory linear verrucous epidermal nevus, 91, 96 Pityriasis rubra pilaris, 92, 97 Psoriasis, 16, 17, 97

Melanoma, 199, 204 Melanoma, balloon cell, 187, 195 Melanoma, desmoplastic, 200, 205

Miscellaneous Atypical fibroxanthoma, 218, 225 Langerhans cell histiocytosis, 136, 140 Leukemia, 155, 240, 244 Lymphoma, 175, 176, 241, 245 Mycosis fungoides, 138, 140 Myeloma (not pictured) Renal cell carcinoma, 189, 195 Subcutaneous T-cell lymphoma, 175, 176

Vascular tumors Angiosarcoma, 70, 78

283

Alphabetical Index

Accessory digit, 3, 7 Accessory nipple, 4, 7 Accessory tragus, 5, 7 Acne keloidalis, 238, 244 Actinic keratosis, 93, 96 Adenoid cystic carcinoma, 80, 83 Aggressive digital papillary adenocarcinoma, 61, 67 Allergic contact dermatitis, 118, 123 Aluminum chloride (Drysol solution), 148, 152 Amyloid, 156, 166, 259, 264 Amyloidosis, nodular, 156, 166 Angiokeratoma, 124, 130 Angioleiomyoma, 68, 78 Angiolipoma, 186 Angiolymphoid hyperplasia with eosinophilia, 69, 78 Angiosarcoma, 70, 78 Apocrine hidrocystoma, 41, 50 Arthropod bite reaction, 119, 123 Aspergillosis, 268, 273 Atypical fibroxanthoma, 218, 225 Auricular pseudocyst, 42, 50 Axillary granular parakeratosis, 94, 97 Bacillary angiomatosis, 71, 78 Balanitis circumscripta plasmacellularis, 139, 140 Basal cell carcinoma, 229, 237 Blastomycosis, 18, 21 Blue nevus, 196, 204 Blue nevus, cellular, 197, 216 Blue nevus, hypopigmented, 153, 155 Bowen disease, 14, 17 Branchial cleft cyst, 43, 50 Bullous pemphigoid/herpes gestationis, 123, 125, 130 Burn, 269, 273 Calcinosis cutis, 54, 157, 166 Chondrodermatitis nodularis helicis, 72, 78 Chondroid syringoma, 246, 249 Chromomycosis, 19, 21

Clear cell acanthoma, 15, 17 Clonal seborrheic keratosis, 98, 106 Coccidioidomycosis, 20, 21 Cryptococcosis, 181, 194 Cutaneous ciliated cyst, 44, 50 Cutaneous endometriosis, 45, 50 Cylindroma, 81, 83 Darier disease, 108, 116 Deep penetrating nevus, 198, 204 Dermatitis herpetiformis, 126, 130 Dermatofibroma, 155, 206, 216 Dermatofibrosarcoma protuberans, 207, 216 Dermatophytosis, 95, 97 Dermoid cyst, 46, 51 Desmoplastic trichoepithelioma, 55, 60 Digital fibrokeratoma, 6, 7 Digital mucous cyst, 250, 256 Dilated pore of Winer, 32, 35 Discoid lupus erythematosus, 87, 96, 244 Elastosis perforans serpiginosa, 52, 54 Epidermal inclusion cyst, 47, 51 Epidermodysplasia verruciformis, 99, 106 Epidermolytic hyperkeratosis, 100, 106 Erythema elevatum diutinum, 260, 264 Erythema induratum, 168, 177 Erythema multiforme, 270, 273 Erythema nodosum, 169, 176 Erythropoietic protoporphyria, 158, 166 Ferric subsulfate (Monsel solution), 149, 152 Fibroepithelioma of Pinkus, 22, 30 Fibrofolliculoma, 23, 30 Fibrous papule, 73, 79 Fixed drug reaction, 141, 147 Flegel disease, 88, 96 Florid papillomatosis (erosive adenomatosis) of the nipple (nipple adenoma) , 62, 67


284

Alphabetical Index

Focal cutaneous mucinosis, 251, 256 Follicular mucinosis, 252, 256 Gel foam, 159, 166 Giant cell tumor of tendon sheath, 219, 225 Glomus tumor, 230, 237 Gout, 36, 40 Graft-versus-host disease, 142, 147 Granular cell tumor, 182, 194 Granuloma annulare, 37, 40, 135, 155 Granuloma faciale, 239, 244 Grover disease, 109, 116 Gyrate erythema, 131, 135 Hailey–Hailey disease, 110, 116 Hemosiderin, 45, 76, 77, 79, 150, 152 Herpes simplex infection, 111, 116, 271, 273 Hibernoma, 183, 194 Hidradenoma papilliferum, 63, 67 Incontinentia pigmenti, 120, 123 Infantile digital fibromatosis, 208, 216 Inflammatory linear verrucous epidermal nevus, 91, 96 Intradermal nevus, 151, 152, 204 Inverted follicular keratosis, 24, 30 Juvenile xanthogranuloma, 192, 195, 220, 225 Kaposi sarcoma, 74, 79, 155, 209, 216 Keratin granuloma, 222, 225 Langerhans cell histiocytosis, 136, 140 Leiomyoma, 210, 216 Leishmaniasis, 152, 184, 194 Lepromatous leprosy, 185, 194 Leukemia, 155, 240, 244 Leukocytoclastic vasculitis, 132, 135 Lichen myxedematosus (not pictured) Lichen nitidus, 143, 147 Lichen planus, 144, 147 Lichen sclerosus et atrophicus, 89, 96, 265, 267 Lichen striatus, 145, 147 Lipodermatosclerosis, 170, 176 Lipoid proteinosis, 160, 166 Lipoma, 176, 186, 194 Lupus profundus, 171, 177 Lupus tumidus, 253 Lymphangioma, 127, 130 Lymphoma, 241, 245 Mastocytoma, 137, 140, 242, 245 Mastocytosis, 137, 140

Melanin, 151, 152, 153, 155, 196, 197, 216 Melanoma, 199, 204 Melanoma, balloon cell, 187, 195 Melanoma, desmoplastic, 200, 205 Merkel cell carcinoma, 231, 237 Metastatic breast carcinoma, 56, 60, 154, 155 Microcystic adnexal carcinoma, 57, 60 Morphea, 8, 13 Morpheaform basal cell carcinoma, 58, 60 Mucinous carcinoma, 247, 249 Mucocele, 248, 249 Mycosis fungoides, 138, 140 Myeloma (not pictured) Myrmecium, 101, 107 Necrobiosis lipoidica, 9, 13, 40 Necrobiotic xanthogranuloma, 38, 40 Neurofibroma, 211, 217 Neurothekeoma, 254, 256 Nevus sebaceous of Jadassohn, 25, 30 Nipple adenoma, 62, 67 Nodular fasciitis, 212, 217, 256 Nodular hidradenoma, 188, 195 Normal back skin, 10, 13 Nutritional deficiency, 97, 272, 273 Ochronosis, 161, 167 Orf, 102, 107 Osteoma cutis, 162, 167 Paget disease, 103, 107 Palisaded encapsulated neuroma, 213, 217 Pancreatic fat necrosis, 172, 177 Papillary eccrine adenoma, 64, 67 Paraffinoma, 163, 167 Pemphigus foliaceus, 112, 117 Pemphigus vegetans, 121, 123 Pemphigus vulgaris, 113, 117 Pigmented purpuric dermatosis, 133, 135 Pigmented spindle cell nevus of Reed, 201, 205 Pilar cyst, 48, 51 Pilar sheath acanthoma, 33, 35 Pilomatricoma, 261, 264 Pityriasis lichenoides et varioliformis acuta, 146, 147 Pityriasis rosea, 134, 135 Pityriasis rubra pilaris, 92, 97 Polyarteritis nodosa, 173, 176 Polymorphous light eruption, 128, 130 Porokeratosis, 90 Poroma, 26, 31 Porphyria cutanea tarda, 129, 130 Pretibial myxedema, 255, 256 Proliferating pilar tumor, 262, 264 Pseudoxanthoma elasticum, 164, 167

Alphabetical Index Psoriasis, 16, 17, 97 Pyogenic granuloma, 75, 79 Radiation dermatitis, 266, 267 Reactive perforating collagenosis, 53, 54 Recurrent nevus, 202, 205 Renal cell carcinoma, 189, 195 Reticulohistiocytosis, 221, 225 Rheumatoid nodule, 39, 40 Ruptured cyst, 222, 225 Sarcoidosis, 223, 225 Scabies, 122, 123 Scar, 214, 217 Schwannoma, 215, 217 Scleredema, 11, 13 Scleromyxedema, 12, 13 Sclerotic fibroma, 263, 264 Sebaceoma (sebaceous epithelioma), 232, 237 Sebaceous adenoma, 190, 195 Seborrheic keratosis, clonal, 98, 106 Seborrheic keratosis, reticulated, 27, 31 Spiradenoma, 233, 237 Spitz nevus, 203, 205 Squamous cell carcinoma, acantholytic, 114, 117 Stasis dermatitis, 76, 79 Steatocystoma, 49, 51 Subcutaneous fat necrosis of the newborn, 174, 177

285

Subcutaneous T-cell lymphoma, 175, 176 Suture granuloma, 224, 225 Sweet syndrome, 243, 245 Syringocystadenoma papilliferum, 65, 67 Syringoma, 59, 60 Targetoid hemosiderotic (hobnail) hemangioma, 77, 79 Tattoo, 152, 165, 167 Trichilemmoma, 28, 31 Trichoadenoma, 82, 83 Trichoblastoma, 234, 237 Trichoepithelioma, 235, 237 Trichofolliculoma, 34, 35 Tubular apocrine adenoma, 66, 67 Tufted angioma, 236, 237 Tumor of the follicular infundibulum, 29, 31 Verruca plana, 104 Verruca vulgaris, 105 Warty dyskeratoma, 115, 117 Xanthelasma, 191, 195 Xanthogranuloma, 192, 195, 220, 225 Xanthoma, 193, 195 Zoon balanitis (balanitis circumscripta plasmacellularis), 139, 140

Dermatopathology: Diagnosis by First Impression, 2nd Edition

Dermatopathology: Diagnosis by First Impression

First Impression

ELECTROMAGNETIC theory - first edition revised impression 1958

Dermatopathology: Third Edition