6/25/2005 Dermatopathology Cribs for General 11/856 Pathologists and Dermatologists Created by Marc R. Hapke, MD that you find a few necrotic

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1 6/25/2005 Dermatopathology Cribs for General 10/856 round cells, variably collagenous stroma, adipose tissue, and branched, often thickwalled, hemangiopericytoma-like vessels. For 11 tumors, the mitotic activity ranged from 1 to 3 mitoses per 10 high-power fields (HPF). One tumor which contained hypercellular areas showed 13 mitoses per 10 HPF, and another hypercellular lesion showed up to 43 mitoses per 10 HPF, abnormal mitoses, and necrosis. Immunohistochemically, tumor cells were invariably positive for vimentin and CD99, and mostly for CD34 but negative for desmin, keratin, CD31, CD117 (c-kit), and inhibin. About half of the tumors showed reactivity for bcl-2. Occasionally, focal reactivity was also observed for smooth muscle actin, muscle-specific actin, S100 protein, and epithelial membrane antigen. Ultrastructural examination of seven cases showed features in keeping with fibroblastic, myofibroblastic, or pericytic differentiation. Treatment consisted of simple tumorectomy in 10 cases and wide excision in 3. Follow-up information on 10 patients (range: 6 to 77 months; median: 18 months) showed no recurrence. Lipomatous hemangiopericytoma which share the clinical, pathologic, immunohistochemical, and ultrastructural features of solitary fibrous tumor (SFT) is likely to represent, in most cases, a fat-containing variant of SFT. Tardio, J. C. and L. M. Martin-Fragueiro (2004). "Angiomyxolipoma (vascular myxolipoma) of subcutaneous tissue." Am J Dermatopathol 26(3): Three cases of angiomyxolipoma (vascular myxolipoma) have been published to date. We report an angiomyxolipoma located in the subcutaneous tissue of the scalp. Histologically, it consisted of an admixture of paucicellular myxoid areas and mature fat tissue, both containing numerous dilated blood vessels with hyalinized thin walls. The cells in the myxoid areas expressed CD34. This lesion requires differential diagnosis with other benign fat tissue tumors, especially myxoid spindle cell lipoma, superficial angiomyxoma, myxoid liposarcoma, and low-grade myxofibrosarcoma. This is not intended to be another textbook of dermatopathology. The field is already crowded with many excellent textbooks dealing with virtually every aspect of the subject. Yet, the lowly punch biopsy of an inflammatory skin condition or an adnexal tumor or a pigmented skin lesion continues to confound the general surgical pathologist as well as the practicing dermatologist who is reading his/her own cases. This book, although it should be useful to the practicing dermatologist as well as to the general pathologist, is primarily directed to general anatomic pathologists for use at the microscope when he/she is dealing with one of these perplexing cases, and must be used in conjunction with at least one of the many general or inflammatory dermatopathology texts. Skin pathology is like any other branch of anatomic pathology in the sense that if one understands the gross appearance of the lesion, one is often more than halfway to reaching the correct diagnosis. For this reason it is easier for a clinical dermatologist with only a middling interest in anatomic pathology principles to practice dermatopathology than it is for an excellent surgical pathologist to do so. Thus, the approach presented in this book represents an anatomic pathologist s attempt to organize an approach to skin pathology which has been evolving over the past 20 years of my practice. This approach involves a consideration of whatever clinical data has been supplied [the more, the better; often none] together with a careful examination of the biopsy in multiple serial step sections [this is extremely important!] to determine its salient histopathological characteristics. A hypothesis is then constructed based upon what the pathologist determines to be the primary pathologic change and what changes are derivative. For example facing an inflammatory skin biopsy you might be uncertain whether the primary process is an interface dermatitis, vacuolar type versus early spongiosis. Your first hypothesis might be this is an interface dermatitis. You must then determine what other significant histopathologic features are present. Let s assume

2 6/25/2005 Dermatopathology Cribs for General 11/856 that you find a few necrotic keratinocytes or perhaps some dyskeratosis in the epidermis. You can then approach the differential from several viewpoints: interface dermatitis, either vacuolar or lichenoid; necrotic keratinocytes, focal spongiosis, or focal parakeratosis. You turn to the table of contents or index to find necrotic keratinocytes or dyskeratotic cells, or any of the other categories and peruse these lists for a condition which is either an interface dermatitis or a spongiotic dermatitis featuring necrotic keratinocytes. Mixing and matching among these various lists will significantly narrow your histologic differential choices. It may be that despite careful study of the biopsy and with reference to chapter 138 [ Early Spongiosis vs. Early Vacuolopathy] you will be unable to decide which of the two mechanisms is at work in a particular biopsy. You can always pursue both mechanisms and offer a differential based upon where a consideration of each of the two mechanisms leads you. After you decide what you think is the basic pathologic process, you must then make a judgment as to which of the remaining findings are important pathologic processes and use the lists to further narrow your differential. One thing that is difficult for us pathologists who have not had formal training in clinical dermatology is to be sure that we keep our diagnostic considerations reasonable possibilities based upon what we already know about the biopsy [patient s age, sex, location and type of lesion, clinician s differential diagnosis, etc., plus what you have already observed]. For this reason it is important for any pathologist who reads many skin biopsies to keep a clinical dermatology text at hand. It helps to keep you honest and keeps you from offering what may be from a clinician s perspective, a patently foolish differential diagnosis. A similar process is followed in the approach to the always perplexing adnexal and vascular tumors. These lists are intended to act as a memory jog and to aid you in the most efficient use of one or more of the larger texts. The idea is to focus your search rather than for you to have to thumb through a variety of textbooks, each of which has a slightly different approach to any particular problem, and all of which have different pictures, looking for something that may fit what you are seeing. By using this method you will at least get to the correct set of pictures in the general texts more easily and less randomly. Another way to use this book, especially when the biopsy has been obtained by a clinician other than a dermatologist, is to note all of the histopathologic features of the biopsy, make a judgment as to which isubacutere pathogenetically important (i.e., are the extravasated erythrocytes part of the inflammatory process or could they be due to the trauma of the biopsy itself?), turn to the index and compare the lists of conditions found under the various headings. When you find a few diseases or entities which appear in more than one of the lists, this gives you a lead to follow. In this manner a biopsy which is submitted with a clinical diagnosis of rash or dermatitis or with no clinical impression at all may be narrowed to a few reasonable possibilities. One caveat must always be kept in mind when looking at a skin biopsy, and that is if you don t see any pathologic changes under the microscope, or if what you see doesn t make sense based upon the clinical impression, get more step serial sections! Many an obvious pathologic process has been discovered with deeper sections when the initial sections were inconclusive. Perforating folliculitis stands as only one good example. I have seen cases of this in which the first four sets of serial sections showed only nonspecific changes which did not fit with the clinical description of the lesions, i.e., crusted papules. The deeper sections showed the lesion in textbook fashion, and it could have easily been missed had not the deeper sections been obtained. Always keep in mind that whether or not you see a lesion under the microscope, the patient and clinician must have seen or felt something to have taken the step of obtaining a skin biopsy. You owe them the effort of obtaining and studying the deeper levels of this biopsy rather than sending out a report of chronic nonspecific dermatitis or no pathologic abnormalities. Occasionally, even after careful study, you may be forced to render such a diagnosis, but at least you will be able to offer a differential diagnosis which may be of some clinical utility. [see section 1, mimics of normal skin ] This book is not intended to replace or even to imitate any of the algorithmic approaches which have become so popular recently. Its use actually supplements the algorithms because it approaches a diagnosis in a different way, that is, more inductively than deductively. Not infrequently, when using these algorithms, the pathologist may trace the histopathologic findings through to a diagnosis which does not make any sense in the context of the clinical data. In any

3 6/25/2005 Dermatopathology Cribs for General 12/856 case if the findings are somewhat nonspecific as they often are, you are not always presented with a good differential diagnosis. Many times a disease will not manifest the classical features presented in the algorithms, and the pathologist may find him/herself getting lost. Psoriasis comes to mind as a cogent example of such a disease process, but many others could be cited as well. In such cases you simply do as suggested above when faced with a biopsy from a nondermatologist clinician to arrive at a reasonable set of diagnostic possibilities and to be able to expand upon the choices offered by the algorithm. I hope users of this book find it helpful in their daily practice. All suggestions for additions, deletions, improvements, etc. will be given serious consideration in an effort to make this volume as useful as possible. DERMATOPATHOLOGY AND DERMATOLOGY TEXTS TO SUPPLEMENT THE USE OF THIS BOOK: Ackerman AB, Chongchitnant N, Sanchez J, Guo Y. Histologic Diagnosis of Inflammatory Skin Diseases: An Algorithmic Method Based on Pattern Analysis. Second Edition. Baltimore: Williams & Wilkins, [Dr. Ackerman has written or supervised the production of a plethora of books and monographs on virtually all aspects of cutaneous pathology, an oeuvre far too lengthy to list here]. Barnhill RL, Crowson AN, Busam KJ, Granter SR. [Eds.] Textbook of Dermatopathology. New York: McGraw-Hill, A most useful text because of its extensive coverage and differential diagnoses. Elder D, Elanitsas R, Jaworsky C, Johnson, Jr. B. [Eds.] Lever Histopathology of the Skin. 8 th edition. Philadelphia: Lippincott-Raven, [a must-read for the dermatopathology boards!] Elder DR, Murphy GF. Melanocytic Tumors of the Skin. Atlas of Tumor Pathology. Third series, vol. 2, Washington, DC: AFIP, Farmer ER, Hood AF. [Eds.] Pathology of the Skin. Norwalk, CT: Appleton & Lange, 2nd Ed., Fitzpatrick TB, Eisen AZ, Wolff K, et al. [Eds.] Dermatology in General Medicine. Fifth edition. New York: McGraw-Hill, Hood AF, Kwan TH, Burnes DC, Mihm MC. Primer of Dermatopathology. Second edition. Boston:Little-Brown, Hurwitz S. Clinical Pediatric Dermatology: a textbook of skin disorders of childhood and adolescence. Second edition. Philadelphia: WB Saunders Company, Maize JC, Burgdorf WHC, Hurt MA, et al. Cutaneous Pathology. Philadelphia: Churchill Livingstone, McKee PH. Pathology of the Skin. Second edition. London: Mosby-Wolfe, 1996.

4 6/25/2005 Dermatopathology Cribs for General 832/856 zinc deficiency & hypogranulosis...64 Zinc deficiency acrodermatitis enteropathica neuts in the horn...54 pustular dermatitis Zoon s balanitis dermal hemosiderin deposits Zygomycetes microscopic features in tissue TABLE OF CONTENTS 27A. CONDITIONS WITH INCREASED LANGERHANS CELLS 2 1. DIFFERENTIAL DIAGNOSIS OF NORMAL-APPEARING SKIN BIOPSY 13 APPROACH TO THE NORMAL APPEARING SKIN BIOPSY CAUSES OF FOLLICULAR PLUGGING KERATIN PLUGGING CAUSES OF ERYTHRODERMA / EXFOLIATIVE DERMATITIS 29 3A. CUTANEOUS DISEASES 29 3B. SYSTEMIC DISEASES CUTANEOUS MUCINOSES 32 A. DERMAL 32 B. FOLLICULAR SKIN CONDITIONS WITH INCREASED DERMAL MUCIN 36

5 6/25/2005 Dermatopathology Cribs for General 833/856 A. EPIDERMAL MUCINOSIS 36 B. DERMAL MUCIN 36 C. FOLLICULAR CAUSES OF MARKED PAPILLARY DERMAL EDEMA CONDITIONS WITH INCREASED NUMBERS OF NEUTROPHILS IN THE STRATUM CORNEUM [ACKERMAN S NEUTS IN THE HORN ] [INCLUDING INTRACORNEAL PUSTULES] CONDITIONS WITH STELLATE MESENCHYMAL CELLS & OTHER MULTINUCLEATED CELLS IN PAPILLARY DERMIS CONDITIONS WITH EPIDERMAL LYMPHOCYTIC EXOCYTOSIS SPONGIFORM PUSTULES HYPOGRANULOSIS WITH SURFACE-TYPE KERATINIZATION HYPERGRANULOSIS EPIDERMOLYTIC HYPERKERATOSIS CHRONIC ECZEMATOUS DERMATITIS EXFOLIATIVE DERMATITIS FOCAL PARAKERATOSIS 65

6 6/25/2005 Dermatopathology Cribs for General 834/ MYCOSIS FUNGOIDES-LIKE CHANGES IN EPIDERMIS (PSEUDO PAUTRIER, PAUTRIER-LIKE CHANGES DUE TO EITHER ATYPICAL LYMPHOCYTES OR ATYPICAL MONOCYTES, PERHAPS MONOCYTOID B-CELLS) CUTANEOUS INFILTRATES WITH INCREASED NUMBERS OF PLASMA CELLS 71 PLASMACYTOSIS MUCOSAE 71 CUTANEOUS LESIONS WHICH CHARACTERISTICALLY FEATURE PLASMA CELLS 72 CUTANEOUS LESIONS WHICH OFTEN FEATURE PLASMA CELLS 72 INFECTIOUS CAUSES: SPONGIOTIC VESICLES INTRAEPIDERMAL BULLAE 81 INTRACORNEAL 81 SUBCORNEAL 82 INTRASPINOUS 82 SUPRABASILAR SUBCORNEAL PUSTULES [PUSTULAR DERMATITIS] EOSINOPHILIC SPONGIOSIS [ES] EOSINOPHILIC EXOCYTOSIS INTRAEPIDERMAL EOSINOPHILIC MICROABSCESSES 89 24A. CAUSES OF NEUTROPHILIC SPONGIOSIS BALLOONING AND RETICULAR DEGENERATION OF EPIDERMIS RETICULAR DEGENERATION OF EPIDERMIS. SECTION ACANTHOLYSIS 92

7 6/25/2005 Dermatopathology Cribs for General 835/ INTRAEPIDERMAL EPITHELIOMA GROWTH PATTERN BORST-JADASSOHN EFFECT EPIDERMAL ATROPHY CORNOID LAMELLA CORNOID LAMELLAE LESIONS CHARACTERIZED BY POIKILODERMATOUS CHANGE SUBEPIDERMAL BULLAE (SUBEPIDERMAL VESICULAR DERMATITIS) NON-INFLAMMATORY AND PAUCI-INFLAMMATORY SUBEPIDERMAL BULLAE 102 CELL POOR 103 WITH SOME INFLAMMATION A. PATTERNS OF DEPOSITION OF IMMUNOREACTANTS IN IMMUNOFLUORESCENCE MICROSCOPY OF SELECTED SKIN DISEASES BANDLIKE INFILTRATE AT DERMOEPIDERMAL JUNCTION SUPERFICIAL PERIVASCULAR [SPV] INFLAMMATORY CONDITIONS 114 MIXED INFILTRATE WITHOUT EVIDENCE OF VASCULAR DAMAGE 115 MIXED INFILTRATE WITH VASCULAR DAMAGE (FIBRINOID NECROSIS) 115 PREDOMINANTLY LYMPHOCYTIC INFILTRATE [SUPERFICIAL PERIVASCULAR LYMPHOHISTIOCYTIC INFLAMMATORY INFILTRATE WITHOUT SPONGIOSIS OR OTHER REACTION PATTERN [SEE SECTION 82, CONDITIONS IN WHICH EXTRAVASATED ERYTHROCYTES ARE IMPORTANT ] SUPERFICIAL & DEEP PERIVASCULAR [SUPERFICIAL AND DEEP PV] INFLAMMATORY CONDITIONS 118 A. PERIVASCULAR INFILTRATE WITHOUT VASCULAR DAMAGE 118 MIXED INFILTRATE 118 LYMPHOCYTIC INFILTRATE [SEE 111, 10 L S ] 118

8 6/25/2005 Dermatopathology Cribs for General 836/856 B. PERIVASCULAR WITH VASCULAR DAMAGE VASCULITIS 119 C. PERIVASCULAR INFLAMMATION WITH VASCULAR THROMBOSIS 119 D. PROMINENT VASCULAR DAMAGE WITH MINIMAL INFLAMMATION NECROTIZING VASCULITIS A. NEUTROPHILIC CAPILLARITIS [KARYORRHEXIS IS NOT A PROMINENT FEATURE] VASCULITIS INVOLVING ARTERIOLES, VENULES AND VEINS LYMPHOCYTIC VASCULITIS [LV] 132 LYMPHOCYTIC VASCULITIS MATERIAL (INCLUDES "COAT-SLEEVE" CUFFING OF VENULES) GRANULOMATOUS VASCULITIS GRANULOMATOUS VASCULITIS 139 LARGE VESSEL 139 SMALL VESSELS COAT-SLEEVE CUFFING OF VESSELS BY SMALL LYMPHOCYTES GRENZ ZONE 152 Management 154 Prognosis 154 REFERENCES FOR PERINEURIOMA GRANULOMAS A. PALISADING GRANULOMAS 157 GRANULOMA ANNULARE MAY PRESENT IIN UNUSUAL LOCATIONS SUCH AS THE PALMS AND SOLES AS PAINFUL LESIONS IN CASES WHERE IT IN FACT REPRESENTS A PARANEOPLASTIC GRANULOMATOUS REACTION TO SOME SOLID ORGAN TUMORS, HD, NON-HODGKIN'S LYMPHOMA OR GRANULOMATOUS MYCOSIS FUNGOIDES B. LESIONS/ENTITIES WHICH MAY BE HISTOLOGIC MIMICS OF PALISADING GRANULOMA 163

9 6/25/2005 Dermatopathology Cribs for General 837/856 44C. EPITHELIOID HISTIOCYTIC GRANULOMAS D. DIFFERENTIAL DIAGNOSIS OF OROFACIAL GRANULOMAS DIFFERENTIAL DIAGNOSIS OF HISTIOCYTOSIS-X (DIFFUSE GRANULOMATOSIS) EPIDERMAL EXOCYTOSIS OF ERYTHROCYTES DIFFERENTIAL DIAGNOSIS OF LYMPHOCYTOMA CUTIS [CUTANEOUS LYMPHOID HYPERPLASIA] DIFFERENTIAL DIAGNOSIS OF THE SQUARE PUNCH BIOPSY A. DIFFERENTIAL DIAGNOSIS OF PERFORATING DISORDERS 173 COMMONLY ACCEPTED FORMS OF PERFORATING DERMATOSES FOLLICULAR MUCINOSIS NECROTIC KERATINOCYTES [NK S] 182 OTHER CONDITIONS WITH NECROTIC KERATINOCYTES: CUTANEOUS THROMBOSIS ALSO KNOWN AS THROMBOTIC VASCULOPATHY OR THROMBOTIC MICROANGIOPATHY WHEN IT OCCURS WITH LYMPHOCYTIC VASCULITIS OR WITHOUT SIGNIFICANT INFLAMMATION. 191 WITH INFLAMMATORY VASCULITIS 191 WITH PERIVASCULAR MIXED INFLAMMATION 191 NONINFLAMMATORY (THROMBOTIC VASCULOPATHY) DIFFUSE HYPERMELANOSIS/HYPERPIGMENTATION HYPOMELANOSIS 194 I. DECREASE IN ACTUAL NUMBER OF MELANOCYTES 194 II. DECREASED MELANIN 195

10 6/25/2005 Dermatopathology Cribs for General 838/ DYSPLASTIC [CLARK S] NEVUS FEATURES [NIH CONSENSUS CONFERENCE AGREED UPON THE TERM ARCHITECTURALLY-DISORDERED MELANOCYTIC NEVUS] 195 CLINICAL FEATURES 197 HISTOLOGIC FEATURES (IBID., 1984) [SEE 132, HISTOLOGIC FEATURES OF RGP MELANOMA, SUBSECTION: IMPORTANT FEATURES OF INVASIVE RADIAL GROWTH PHASE MELANOMA. 197 MAJOR ASYMMETRIC BASILAR PROLIFERATION OF NEVUS CELLS ALONG THE DERMO-EPIDERMAL JUNCTION EXTENDING USUALLY 3 RETE RIDGES OR MORE BEYOND THE DERMAL COMPONENT, IF PRESENT. 198 MINOR PAPILLARY DERMAL COLLAGEN SHOWS EITHER CONCENTRIC OR LAMELLAR EOSINOPHILIC FIBROPLASIA, OR BOTH. IN CONCENTRIC FIBROPLASIA, A DENSE ZONE OF ACELLULAR COLLAGEN ENVELOPS THE RETIA WHILE IN LAMELLAR FIBROPLASIA DELICATE PARALLEL LAYERS OF COLLAGEN ARE INTERSPERSED WITH ELONGATED FUSIFORM CELLS. 198 ARCHITECTURE 199 HOST RESPONSE 199 CYTOLOGY 199 OTHER CRITERIA 201 IMPORTANT NEGATIVES 202 SIGNS OF MELANOMA EVOLVING FROM DYSPLASTIC NEVUS INCLUDE: NEVUS CELLS VS. SMALL MATURING** MELANOMA CELLS OR NEVOID MELANOMA VS ATYPICAL COMPOUND NEVUS (COMPOUND DN WITH SEVERE DYSPLASIA) CONDITIONS ASSOCIATED WITH GLOBULAR DEPOSITS OF IMMUNOGLOBULIN & C3 AT DEJ & IN PAPILLARY DERMIS: DIFFERENTIAL DIAGNOSIS SARCOIDAL GRANULOMAS TYPES OF FUNGAL HAIR PARASITIZATION 210 ECTOTHRIX 210 ENDOTHRIX 210 DIFFERENTIAL DIAGNOSIS OF TINEA CAPITIS: A. IDENTIFYING CHARACTERISTICS OF FUNGI WHICH MAY BE OBSERVED IN SKIN LESIONS BY DIRECT LIGHT MICROSCOPY 211 TERMS 211 TINEA INFECTIONS [7 REGIONS] 212

11 6/25/2005 Dermatopathology Cribs for General 839/ PLASMA CELLS ASSOCIATED WITH GRANULOMATOUS REACTION CAUSES OF SCALE-CRUST (SPONGIOSIS + PARAKERATOSIS) TUMORS OF SKIN WHICH MAY HAVE A PROMINENT CLEAR CELL COMPONENT (SEE 76, FOAM CELLS SEE ALSO S 71, , 151 ADNEXAL TUMORS] PAINFUL (TENDER) SKIN TUMORS HISTOPATHOLOGY OF DRUG-INDUCED DERMATITIS 242 ADDITIONAL CLUES TO A CUTANEOUS DRUG REACTION 243 MORBILLIFORM DRUG ERUPTIONS 245 LICHENOID DRUG ERUPTIONS 246 FIXED DRUG ERUPTIONS 247 PHOTOALLERGIC REACTIONS: 249 DRUG-ASSOCIATED LUPUS ERYTHEMATOSUS [DILE] 251 LYMPHOMATOID DRUG ERUPTIONS 252 DILANTIN [PHENYTOIN] HYPERSENSITIVITY SYNDROME 252 ACNEIFORM DRUG REACTIONS 253 PSORIASIFORM DRUG REACTIONS MICRO-ORGANISMS WHICH ARE USUALLY FOUND IN AN INTRACELLULAR LOCATION 255 [OBLIGATE INTRACELLULAR MICROORGANISMS, PARASITIZED MACROPHAGES] CLASSIFICATION OF ALOPECIAS 255 IA. INFLAMMATORY, NON-SCARRING 255 IB. INFLAMMATORY, SCARRING 255 IIB. NON-INFLAMMATORY, NON-SCARRING 257 TABULAR CLASSIFICATION OF CICATRICIAL ALOPECIAS 257 DEVELOPMENTAL DEFECTS & HEREDITARY DISORDERS 257 INFECTION 257 NEOPLASMS & HAMARTOMAS 258 PHYSICAL/CHEMICAL AGENTS 258 DERMATOSES OF UNCERTAIN ORIGIN & CLINICAL SYNDROMES 258 CLASSIFICATION OF NONCICATRICIAL ALOPECIAS 258 ANDROGENETIC (ANDROGENIC) ALOPECIA 258 HEREDITARY SYNDROMES 259 ALOPECIA AREATA 259

12 6/25/2005 Dermatopathology Cribs for General 840/856 NONCICATRICIAL ALOPECIA ASSOCIATED WITH SYSTEMIC DISEASE OR STATE: 259 DRUGS & CHEMICAL AGENTS 260 TRAUMATIC NONCICATRICIAL ALOPECIA 260 APPROACH TO A BIOPSY OF ALOPECIA 260 MAJOR & ADJUNCTIVE CRITERIA TO CONSIDER IN ALOPECIA BIOPSY 262 PATHOGENETIC MECHANISMS WHICH MAY LEAD TO ALOPECIA CONDITIONS ASSOCIATED WITH DYSKERATOSIS 267 DIFFERENTIAL DIAGNOSIS OF FOCAL ACANTHOLYTIC DYSKERATOSIS PSORIASIFORM DERMATITIS PATTERN 269 I. DISEASES WITH PSORIASIFORM EPIDERMAL HYPERPLASIA AS A CHARACTERISTIC FEATURE: 270 DIFFERENTIAL DIAGNOSIS OF (PITYRIASIS RUBRA PILARIS) PRP IN INTERFOLLICULAR EPIDERMIS: 271 II. DISEASES WHICH FREQUENTLY MANIFEST PSORIASIFORM EPIDERMAL HYPERPLASIA: 272 III. DISEASES WHICH MAY SOMETIMES HAVE A PATTERN OF PSORIASIFORM EPIDERMAL HYPERPLASIA: CATEGORIZATION OF TUMORS AND CYSTS OF THE SKIN BY HISTOPATHOLOGIC CHARACTERISTICS A. PREDOMINANTLY CYSTIC TUMORS A.1. TUMORS WHICH MAY SOMETIMES BE CYSTIC OR HAVE CYSTIC AREAS B. SHADOW ( GHOST ) CELLS C. IEE (INTRAEPIDERMAL EPITHELIOMA D. CLEAR CELLS IN VARYING PROPORTIONS E. TWO CELL TYPES F. TUMORS WHICH DEMONSTRATE DUCTAL OR DUCTULAR DIFFERENTIATION G. MAY APPEAR HYPERVASCULAR H. TYPICALLY SHOWS CONNECTIONS TO OVERLYING EPIDERMIS I. TYPICALLY DOES NOT SHOW CONNECTIONS TO OVERLYING EPIDERMIS K. PERIPHERAL PALISADING OF TUMOR CELL NUCLEI L. INTERCELLULAR BRIDGES VISIBLE M. SQUAMOUS EDDIES OR SQUAMOUS METAPLASIA N. CENTRAL PART OF LESION CONTAINS HAIR SHAFT LESIONS WHICH CONTAIN HAIR SHAFT O. BASALOID CELLS P. KERATINIZES WITH GRANULAR LAYER (GRADUAL, INCOMPLETE KERATINIZATION KERATOHYALINE GRANULES) Q. PROLIFERATION OF NARROW STRANDS AND TINY NESTS OF TUMOR CELLS R. KERATINIZES WITHOUT GRANULAR LAYER (ABRUPT, COMPLETE KERATINIZATION, TRICHOLEMMAL) S. INTRACYTOPLASMIC MELANIN PRESENT (FOUND IN EPITHELIAL TUMORS HAVING MATRICAL DIFFERENTIATION) T. TRICHOHYALINE GRANULES PROMINENT 285

13 6/25/2005 Dermatopathology Cribs for General 841/856 71U. CUTICULAR EPITHELIAL DIFFERENTIATION (THIN HYALINE PINK SURFACE OR AMORPHOUS PINK DEBRIS) V. DECAPITATION SECRETION W. TUMOR GROWS IN A LOBULAR PATTERN IN DERMIS X. PAPILLARY EPITHELIAL INFOLDINGS Y. MAY FORM CUTANEOUS HORN Z. OFTEN FORM ABORTIVE HAIR PAPILLAE AA. STROMAL INDUCTION WITH DESMOPLASIA AB. STROMAL INDUCTION WITHOUT DESMOPLASIA [STROMA IS A COMPONENT OF THE TUMOR/CYST] AC. OFTEN CHARACTERIZED BY MUCINOUS (MYXOID) OR FIBROMYXOID STROMAL REACTION AD. TYPICALLY SHOWS NO STROMAL INDUCTION AE. EOSINOPHILIC HYALINE GLOBULES IN ASSOCIATION WITH TUMOR CELLS AF. PROMINENT BASEMENT MEMBRANE INDUCTION BY TUMOR CELLS AG. STROMAL/EPITHELIAL SEPARATION ARTIFACT AH. TUMOR CELL APOPTOSIS AI. DYSTROPHIC CALCIFICATION AJ. FOREIGN BODY GIANT CELL REACTION AK. FOLLICLE PLUGGING AL. ANASTOMOSING IRREGULAR RETIFORM OR LACE-LIKE EPITHELIAL PROLIFERATION AM INFLAMMATORY CELLS ARE A SIGNIFICANT COMPONENT OF THE TUMOR OR ITS STROMA [INFLAMMATORY CELLS IMPORTANT PART OF LESION] 294 OTHER, NON-ADNEXAL TUMORS INVOLVING THE SKIN IN WHICH INFLAMMATORY CELLS ARE AN IMPORTANT COMPONENT AN. SUPERFICIAL DERMAL LOCATION AO. LESION OR TUMOR CELL PROLIFERATION OPEN TO SKIN SURFACE AP. DEEP DERMAL/SUBCUTANEOUS LOCATION AQ. KERATINOUS (HORN) CYSTS PROMINENT [Q.V., 71AJ, FOREIGN BODY GIANT CELL REACTION] AR. KERATINOUS (HORN) CYSTS VARIABLE AS. ENCAPSULATED ADNEXAL TUMORS AT. CRIBRIFORM PATTERN PRESENT WITHIN TUMOR AT LEAST FOCALLY AU. PATTERNS OF BASAL CELL CARCINOMA TO BE CONSIDERED BEFORE CLASSIFYING A LESION AS AN ADNEXAL TUMOR AV. NEVOID BASAL CELL CARCINOMA SYNDROME [BASAL CELL NEVUS SYNDROME] [REF: PRATT MD, JACKSON R. NEVOID BASAL CELL CARCINOMA SYNDROME. J AM ACAD DERMATOL 1987; 16: ] 302

14 6/25/2005 Dermatopathology Cribs for General 842/856 COMMON VARIANTS OF BCC 302 UNCOMMON VARIANTS AW. PERIVASCULAR SPACES (AS IN THYMOMA) MAY BE PROMINENT WITHIN THE TUMOR DISORDERS SHOWING ANGIOCENTRIC LYMPHOCYTIC INFILTRATES & ASSOCIATED ACUTE OR CHRONIC HEMORRHAGE (Q.V. 41, COAT-SLEEVE PERIVASCULAR CUFFING & 39, LYMPHOCYTIC VASCULITIS ALSO 111, 10 L S 82, EXTRAVASATED RED CELLS ; SEE 18, PLASMA CELL INFILTRATES ; 62, PLASMA CELL & GRANULOMATOUS) CLASSIFICATION OF PANNICULITIS 306 A. PREDOMINANTLY SEPTAL WITH VASCULITIS WITHOUT VASCULITIS 306 B. PREDOMINANTLY LOBULAR WITH VASCULITIS WITHOUT VASCULITIS 308 C. MIXED SEPTAL & LOBULAR 309 D. OTHER SKIN DISORDERS SOMETIMES AFFECTING THE SUBCUTIS 311 APPROACH TO DIAGNOSIS OF PANNICULITIS A. CAUSES OF ACUTE, NEUTROPHILIC PANNICULITIS LESIONS CHARACTERIZED BY ACCUMINATE PROJECTIONS OF KERATIN LESIONS CHARACTERIZED BY PATTERN OF CHRONIC NONSPECIFIC DERMATITIS A. DIFFERENTIAL DIAGNOSIS OF EXANTHEMATOUS DERMATITIS [MORBILLIFORM RASH] DIAGNOSTIC CONSIDERATIONS WHEN FOAM CELLS PREDOMINATE (SEE 64, CLEAR CELL PREDOMINANCE SEE ALSO 71, ADNEXAL TUMORS) PERIFOLLICULAR LYMPHOCYTIC INFILTRATES 319

15 6/25/2005 Dermatopathology Cribs for General 843/ CAUSES OF GRANULAR DEPOSITS OF IGA IN DERMAL VESSEL WALLS SKIN CONDITIONS IN AIDS PATIENTS WHICH ARE COMMONLY SEEN AT DECREASING CD4 COUNTS [SEE COCKEREL, CJ. MUCOCUTANEOUS NEOPLASMS IN PATIENTS WITH HIV INFECTION. SEM DIAG PATHOL 1996; 13:19-39] SKIN DISEASES/CONDITIONS EXACERBATED BY UV IRRADIATION CONDITIONS CHARACTERIZED BY MIXED PLASMA CELL AND EOSINOPHIL INFILTRATES (SEE 18, PLASMA CELL INFILTRATES 62, PLASMA CELLS ASSOCIATED WITH A GRANULOMATOUS REACTION ; 87, CAUSES OF INCREASED DERMAL EOSINOPHILS ) [PLASMA CELLS AND EOSINOPHILS OR EOSINOPHILS AND PLASMA CELLS] CONDITIONS IN WHICH EXTRAVASATED ERYTHROCYTES ARE DIAGNOSTICALLY IMPORTANT (Q.V. 46, EPIDERMAL EXOCYTOSIS OF ERYTHROCYTES 72, ANGIOCENTRIC LYMPHOID INFILTRATES WITH ASSOCIATED ACUTE OR CHRONIC HEMORRHAGE; SEE ALSO 41, COAT-SLEEVE CUFFING BY SMALL LYMPHOCYTES ) CONDITIONS WITH PROMINENT DERMAL MELANOPHAGES (Q.V., 8, STELLATE FIBROBLASTS & 96, HYALINIZING PAPILLARY DERMAL FIBROSIS 28, EPIDERMAL ATROPHY 30, POIKILODERMA ) HPV [HUMAN PAPILLOMAVIRUS] SUBTYPES AND THEIR ASSOCIATED EPITHELIAL LESIONS 351 SUBTYPES WHICH ARE CONSIDERED LOW RISK: 351 SUBTYPES WHICH ARE CONSIDERED HIGH RISK: 351 I. IN PAPILLARY DERMIS 352 B. PERIVASCULAR & INTERSTITIAL 353 II. IN RETICULAR & PAPILLARY DERMIS A. CAUSES OF DERMAL EOSINOPHIL FLAME FIGURES. 357 CH 88. DIFFERENTIAL DIAGNOSIS OF ELASTIC TISSUE DISORDERS 359

16 6/25/2005 Dermatopathology Cribs for General 844/ HYALINIZED VESSELS IN PAPILLARY DERMIS (± TO 4+) ALSO KNOWN AS HYALINE MICROANGIOPATHY VARIOUS HISTOPATHOLOGIC MANIFESTATIONS OF EARLY LYME DISEASE (ERYTHEMA CHRONICUM MIGRANS) 371 A. FOR ERYTHEMA CHRONICUM MIGRANS 372 B. FOR ACRODERMATITIS CHRONICA ATROPHICANS 373 C. FOR BORRELIAL PSEUDOLYMPHOMA VARIOUS HISTOLOGIC MANIFESTATIONS OF PRURITIC URTICARIAL PAPULES & PLAQUES OF PREGNANCY (PUPPP) DIFFERENTIAL DIAGNOSIS OF CUTANEOUS CALCIFICATIONS [INCLUDING SUBCUTIS] 373 DYSTROPHIC 374 LOCALIZED 374 WIDESPREAD 374 METASTATIC 374 HYPERCALCEMIC 374 NORMOCALCEMIC 375 IDIOPATHIC 375 LOCALIZED 375 GENERALIZED SKIN LESIONS WHICH MAY KOEBNERIZE (ISOMORPHIC RESPONSE) CUTANEOUS MANIFESTATIONS OF DIETARY/METABOLIC DISORDERS A. CUTANEOUS MANIFESTATIONS OF SYSTEMIC DISEASES 378 DISEASES WITH HEART AND SKIN INVOLVEMENT 378 DISEASES WITH PROMINENT CUTANEOUS AND RENAL MANIFESTATIONS 379 SKIN DISEASES ASSOCIATED WITH HEMODIALYSIS 379 RENAL TRANSPLANT PATIENTS 380 SYSTEMIC INFECTIONS 380 CUTANEOUS MANIFESTATIONS OF INTERNAL MALIGNANCY 380 HORMONE-RELATED CONDITIONS 381 OTHER DISORDERS ASSOCIATED WITH INTERNAL MALIGNANT DISEASE 381 SKIN CHANGES DUE TO MALABSORPTION 382

17 6/25/2005 Dermatopathology Cribs for General 845/ DIFFERENTIAL DIAGNOSIS OF CHRONIC INTERFACE DERMATITIS PATTERN OF FOCAL, HYALINIZING PAPILLARY DERMAL FIBROSIS (I.E., LICHENIFICATION OF PAPILLARY DERMIS, OFTEN WITH DERMAL MELANOPHAGES) A. DIFFERENTIAL DIAGNOSIS OF INTERFACE DERMATITIS 384 VACUOLAR INTERFACE 385 DIFFERENTIAL DIAGNOSIS OF GVHD 388 LICHENOID INTERFACE MUCOUS MEMBRANE CONDITIONS WITH NEUTROPHILS IN THE STRATUM CORNEUM [Q.V., 7, EPIDERMAL DISEASES WITH NEUTROPHILS IN STRATUM CORNEUM] A. CONDITIONS ASSOCIATED WITH PSEUDOEPITHELIOMATOUS [PSEUDOCARCINOMATOUS] HYPERPLASIA [PEH] WITH ACUTE/SUBACUTE INFLAMMATION. [PSEUDOEPITHELIOMATOUS HYPERPLASIA = HYPERPLASIA OF INFUNDIBULAR OR ECCRINE DUCTAL KERATINOCYTES] ALSO PSEUDOEPITHELIOMATOUS EPIDERMAL HYPERPLASIA PARASITIC INFESTATIONS 398 OTHER B. DIFFERENTIAL HISTOPATHOLOGIC FEATURES OF PSEUDOEPITHELIOMATOUS HYPERPLASIA, WELL-DIFFERENTIATED SQUAMOUS CARCINOMA AND KERATOACANTHOMA DISEASES/CONDITIONS MANIFESTING FOCAL SPONGIOSIS CAUSES OF CYTOTOXIC DERMATITIS CAUSES OF SATELLITE CELL NECROSIS CONDITIONS ASSOCIATED WITH TELANGIECTATIC OR PROLIFERATED VESSELS IN PAPILLARY DERMIS CAUSES OF NEUTROPHIL EXOCYTOSIS 411

18 6/25/2005 Dermatopathology Cribs for General 846/ CLASSIFICATION OF PARAPSORIASIS 417 I. LARGE PLAQUE PARAPSORIASIS [LPP] 417 A. PARAPSORIASIS EN PLAQUES [PEP] 417 B. VARIEGATE [RETIFORM] PARAPSORIASIS 417 II. SMALL PLAQUE PARAPSORIASIS [SPP] [DIGITATE DERMATOSIS, BROCQ S DISEASE, CHRONIC SUPERFICIAL DERMATITIS, GUTTATE PARAPSORIASIS] 417 III. PITYRIASIS LICHENOIDES GROUP 418 A. PITYRIASIS LICHENOIDES AND VARIOLIFORMIS ACUTA [PLEVA] 418 B. PITYRIASIS LICHENOIDES CHRONICA (PLC) PAPULOSQUAMOUS SKIN CONDITIONS 419 DEFINITION: DERMATOLOGIC CONDITIONS WHICH MAY RESULT IN ANNULAR/FIGURATE [GYRATE] ERYTHEMAS CAUSES OF GRANULOCYTIC (PHLEGMONOUS) DERMATITIS LESIONS WHICH MAY CAUSE A FOLLICULOCENTRIC RASH SPINDLE CELL PROLIFERATIONS OF THE SKIN AND SUBCUTIS A. LESIONS AFFECTING SKIN & SUBCUTIS AND MANIFESTING MULTINUCLEATED GIANT CELLS [MNGC] AS AN INTEGRAL FEATURE OF THEIR HISTOLOGIES. 458 INFLAMMATORY/NON-NEOPLASTIC/INFECTIOUS 466 BENIGN TUMORS WITH PLEOMORPHIC CELLS B. SKIN TUMORS WHICH MAY MANIFEST A STORIFORM PATTERN C. DIFFERENTIAL CONSIDERATIONS OF EPITHELIOID LESIONS AFFECTING THE SKIN AND SUBCUTIS. 470 MALIGNANT 470 TUMORS OF UNCERTAIN BEHAVIOR 471 BENIGN 471

19 6/25/2005 Dermatopathology Cribs for General 847/ D. DIFFERENTIAL DIAGNOSIS OF MYXOID NEOPLASMS WHICH MAY INVOLVE THE SKIN AND SUBCUTIS E. FATTY TUMORS THAT MAY INVOLVE THE SKIN HISTIOCYTIC AND HISTIOCYTE-LIKE SKIN INFILTRATES IN CHILDREN AND YOUNG ADULTS CAUSES OF RETICULAR DERMAL EDEMA PATCHY DERMAL LYMPHOHISTIOCYTIC [LYMPHOCYTIC] INFILTRATES. PERIFOLLICULAR LHI* [ 10 L S PLUS 4; 10 L S OR 5 L S OR 8 L S] [5 L S, 8 L S, 10 L S ] INFLAMMATORY DERMATITIDES WITH EPIDERMAL INVOLVEMENT WHICH FEATURE PRESERVATION OF THE NORMAL BASKETWEAVE ORTHOKERATOSIS AT LEAST EARLY IN THEIR COURSE SQUAMATIZATION [SQUAMOTIZATION] OF EPIDERMAL BASAL CELL LAYER AS A DISEASE CHARACTERISTIC [PREMATURE TERMINAL DIFFERENTIATION OF BASAL KERATINOCYTES] LESIONS WITH PAPILLARY DERMAL MICROABSCESSES BULLOUS DISORDERS WITH FESTOONED BASEMENT MEMBRANE ZONE [SEE 31, SUBEPIDERMAL BULLAE & 32, NON-(OR PAUCI) -INFLAMMATORY SUBEPIDERMAL BULLAE 133, BULLOUS CONDITIONS WITH NECROSIS OF ADNEXAL STRUCTURES] PITYRIASIFORM DERMATITIDES CAUSES OF INCREASED DERMAL NEUTROPHILS 486

20 6/25/2005 Dermatopathology Cribs for General 848/ INFLAMMATORY SKIN CONDITIONS ASSOCIATED WITH PERIADNEXAL [INCLUDES ECCRINE COILS & FOLLICLE] LYMPHOHISTIOCYTIC INFILTRATES CONDITIONS IN WHICH INFLAMMATORY OR NEOPLASTIC CELLS TEND TO LINE UP ALONG EPIDERMAL BASEMENT MEMBRANE ZONE. CELLS LINE UP ALONG BMZ (PUT IN FOR FINDING THIS IN WORD) CONDITIONS FEATURING PALLOR OF EPIDERMAL OR MUCOSAL KERATINOCYTES CONDITIONS FEATURING LANGERHANS CELL MICROGRANULOMAS OR OTHER MONONUCLEAR CELL MICROGRANULOMAS IN EPIDERMIS OR IN FOLLICULAR INFUNDIBULAR EPITHELIUM ( PSEUDOPAUTRIER MICROABSCESSES ) BULLOUS CONDITIONS WITH DERMAL SCARRING FEATURES WHICH SHOULD SUGGEST A DELAYED-TYPE HYPERSENSITIVITY REACTION [ALSO TERMED DERMAL HYPERSENSITIVITY REACTION & DTH] CONDITIONS WHICH RESULT IN INCREASED DERMAL CELLULARITY THE SO- CALLED BUSY DERMIS. 512 INFLAMMATORY CONDITIONS 512 NON-NEOPLASTIC TUMORS OR SWELLINGS 514 NEOPLASTIC CONDITIONS COMPARISON OF KAMINO BODIES SEEN IN SPITZ NEVUS VS. THOSE SEEN IN MELANOMAS PREGNANCY DERMATOSES [SEE ALSO 92, PUPPP & 128, COMPARISON OF PEMPHIGOIDES GESTATIONIS WITH PUPPP] 519 CLINICALLY WELL-DEFINED 519 CLINICALLY POORLY-DEFINED HISTOPATHOLOGIC MANIFESTATIONS OF PUPPP 519

21 6/25/2005 Dermatopathology Cribs for General 849/ CONDITIONS IN WHICH MAST CELLS MAY BE PROMINENT DIFFERENTIAL CRITERIA BETWEEN MELANOMA AND SPITZ NEVUS 522 CLASSICAL PAPERS ON THE HISTOPATHOLOGIC DIAGNOSIS OF SPITZ TUMOR AND THE DIAGNOSTIC CRITERIA PROPOSED IN THEM 522 CRITERIA FAVORING SPITZ NEVUS CHARACTERISTICS OF THE VERTICAL [INVASIVE] GROWTH PHASE OF MELANOMA 528 THE AFIP FASCICLE ON MELANOCYTIC TUMORS OF THE SKIN BY MURPHY AND ELDER [3 RD SERIES] USES THREE MAJOR AND SEVERAL MINOR CRITERIA TO DEFINE VGP MELANOMA: 529 MAJOR 529 MINOR MICROSCOPIC FEATURES OF RADIAL GROWTH PHASE [RGP] MELANOMA 531 HISTOLOGIC CRITERIA FOR REGRESSION IN MELANOMA 532 EARLY 532 INTERMEDIATE 532 LATE A. IMPORTANT FEATURES OF INVASIVE RADIAL GROWTH PHASE 535 MELANOMA 535 HISTOLOGIC CRITERIA FOR REGRESSION IN MELANOMA 536 REFERENCES ON THIN MELANOMA BULLOUS CONDITIONS IN WHICH SWEAT GLAND NECROSIS MAY BE SEEN. ALSO OFTEN SEE NECROSIS OF OTHER ADNEXAL STRUCTURES DIFFERENTIAL DIAGNOSTIC FEATURES IMPORTANT IN DIFFERENTIATING COMMON BLUE NEVUS FROM REGRESSED PRIMARY MALIGNANT MELANOMA 542 HISTOLOGIC CRITERIA FOR REGRESSION IN MELANOMA A. DIFFERENTIAL FEATURES BETWEEN DESMOPLASTIC MELANOMA AND BLUE NEVUS. 545

22 6/25/2005 Dermatopathology Cribs for General 850/856 CH. 134B. DESMOPLASTIC MELANOMA VS. DESMOPLASTIC NEVUS [SEE: 134A, DESMOPLASTIC MELANOMA VS. BLUE NEVUS] CLUES TO A DRUG REACTION INTERSTITIAL EOSINOPHILS DYSKERATOSIS VS. HYPERKERATOSIS 551 DIFFERENTIAL DIAGNOSIS OF FOCAL ACANTHOLYTIC DYSKERATOSIS EARLY SPONGIOSIS VS. BASAL VACUOLOPATHY 552 B. EARLY SPONGIOSIS [SS A1] 552 C. OTHER CHANGES ALOPECIA CLUES 553 LICHEN PLANOPILARIS [LPP] 553 DLE 554 FOLLICULAR DEGENERATION SYNDROME (FORMERLY REFERRED TO AS INFLAMMATORY PSEUDOPELADE AND HOT-COMB ALOPECIA) 555 ALOPECIA AREATA 555 TRACTION ALOPECIA/TRICHOTILLOMANIA 557 MALE PATTERN BALDNESS [ANDROGENETIC, MALE & FEMALE] 557 TELOGEN EFFLUVIUM 557 SECONDARY SYPHILIS[SYPHILITIC ALOPECIA; LUETIC ALOPECIA] 558 END-STAGE ALOPECIA (OFTEN REFERRED TO LOOSELY AS PSEUDOPELADE OF BROCQ; PPOB) 559 COMMON FEATURES OF MANY FORMS OF NON-SCARRING ALOPECIA 559 NEUTROPHILIC FOLLICULITIDES 559 FOLLICULITIS DECALVANS 559 ACNE KELOIDALIS (FOLLICULITIS KELOIDALIS NUCHAE) 560 FOLLICULAR OCCLUSION TRIAD (TETRAD IF INCLUDE PILONIDAL SINUS) 560 ACNE CONGLOBATA 560 DISSECTING CELLULITIS (FOLLICULITIS ET PERIFOLLICULITIS ABSCEDENS ET SUFFODIENS) 560 HIDRADENITIS SUPPURATIVA EPIDERMOTROPIC METASTATIC MELANOMA VS. PRIMARY MELANOMA CLUES FROM PATTERNS OF HYPERKERATOSIS AND PARAKERATOSIS 562

23 6/25/2005 Dermatopathology Cribs for General 851/856 TYPES OF PARAKERATOSIS [ILLUSTRATE] DERMATITIDES FEATURING ABUNDANT KARYORRHECTIC DEBRIS IN THE DERMIS, ADNEXAL TUMORS & CYSTS CLASSIFIED ACCORDING TO THEIR DOMINANT MORPHOLOGIC FEATURES. 570 CYSTIC, EITHER ENTIRELY OR IN PART 570 TUMORS FORMING NESTS, CORDS & DUCTULAR STRUCTURES 571 TUMORS FORMING MOSTLY SHEETS & SOLID NODULES ADNEXAL TUMORS & CYSTS CLASSIFIED ACCORDING TO PRESUMED HISTOGENESIS 572 DIFFERENTIATION PRIMARILY TOWARD HAIR STRUCTURES 572 HYPERPLASIAS, HAMARTOMAS & CYSTS 572 BENIGN NEOPLASMS 573 MALIGNANT NEOPLASMS 574 DIFFERENTIATION PRIMARILY TOWARD SEBACEOUS GLANDS 574 HYPERPLASIAS, HAMARTOMAS & CYSTS 574 BENIGN NEOPLASMS 574 MALIGNANT NEOPLASMS 575 DIFFERENTIATION PRIMARILY TOWARD APOCRINE GLANDS 575 HYPERPLASIAS, HAMARTOMAS & CYSTS 575 BENIGN NEOPLASMS 575 MALIGNANT NEOPLASMS 575 DIFFERENTIATION PRIMARILY TOWARD ECCRINE GLANDS 575 HYPERPLASIAS, HAMARTOMAS & CYSTS 575 BENIGN NEOPLASMS 575 MALIGNANT NEOPLASMS ANATOMY & PHYSIOLOGY OF THE ADULT HUMAN HAIR FOLLICLE 576 NAMED PARTS OF THE ANAGEN HAIR BULB HAIR FOLLICLE TUMORS RELATED TO THE ANATOMY OF THE HAIR FOLLICLE ] 577 PILOSEBACEOUS COMPLEX AS A WHOLE 577 TUMORS 577 INFUNDIBULUM 577 TUMORS 577 CYSTIC LESIONS 578 ISTHMUS 578 TUMORS OF EXTERNAL HAIR SHEATH 578 SEBACEOUS GLANDS 578

24 6/25/2005 Dermatopathology Cribs for General 852/856 TUMORS 578 ARRECTOR PILI MUSCLE 579 TUMORS 579 HAIR BULB 579 MATRIX & PAPILLA 579 TUMORS CLASSIFICATION OF TUMORS WITH APOCRINE DIFFERENTIATION ACCORDING TO PART OF APOCRINE GLAND TO WHICH THEY ARE RELATED ] 579 ENTIRE APOCRINE APPARATUS 579 SECRETORY COIL 579 DUCT STRUCTURES 579 UNKNOWN CLASSIFICATION OF TUMORS WITH ECCRINE GLAND DIFFERENTIATION ACCORDING TO THEIR RELATIONSHIP TO DIFFERENT PARTS OF THE ECCRINE GLAND 580 ENTIRE ECCRINE APPARATUS 580 INTRAEPIDERMAL PORTION OF ECCRINE DUCT 580 DERMAL PORTION OF ECCRINE DUCT 580 ECCRINE SECRETORY COIL 580 SECRETORY COIL & INTRAEPIDERMAL PORTION OF DUCT 580 INTRAEPIDERMAL & INTRADERMAL PORTION OF ECCRINE DUCT 580 UNKNOWN FIBROSING PROCESSES IN THE SKIN 581 SUPERFICIAL DERMIS [PAPILLARY & UPPER RETICULAR] 581 INFLAMMATORY 581 NONINFLAMMATORY 582 MID & DEEP DERMIS INCLUDING SUBCUTIS SOMETIMES 583 INFLAMMATORY 583 NONINFLAMMATORY 585 PANDERMAL 586 INFLAMMATORY 586 NONINFLAMMATORY PIGMENTED SKIN LESIONS [PART A] DESCRIPTIONS OF COMMON ADNEXAL NEOPLASMS GROUPED ACCORDING TO DOMINANT HISTOLOGIC PATTERN. 594 PARTIALLY & FULLY CYSTIC LESIONS [PART A] 594

25 6/25/2005 Dermatopathology Cribs for General 853/856 EPIDERMAL INCLUSION CYST (EPIDERMOID CYST PILAR CYST, INFUNDIBULAR TYPE INFUNDIBULAR CYST) 594 TRICHOLEMMAL CYST (PILAR CYST, ISTHMUS CATAGEN TYPE TRICHOCHLAMYDOCYST) 594 HAIR MATRIX CYST KERATIN-FILLED CYST WITHIN MID-DERMIS MAY HAVE SHADOW CELLS. [SEE 71B] 595 ERUPTIVE VELLUS HAIR CYST (EVHC S) 596 DERMOID CYST 597 POROKERATOTIC ECCRINE DUCT NEVUS 597 DILATED PORE (OF WINER) 597 PILAR SHEATH ACANTHOMA 597 BRONCHOGENIC & THYROGLOSSAL DUCT (TGD) CYSTS 598 BRONCHOGENIC 598 THYROGLOSSAL DUCT CYST (TGD CYST) 598 MEDIAN RAPHE CYST OF PENIS 599 STEATOCYSTOMA 599 CUTANEOUS CILIATED CYST 599 ECCRINE HIDROCYSTOMA (CYSTADENOMA) 600 SYRINGOCYSTADENOMA PAPILLIFERUM 600 HIDRADENOMA PAPILLIFERUM (PAPILLARY HIDRADENOMA [SS ,A1]) 600 PILOMATRICOMA 601 NODULAR HIDRADENOMA & MALIGNANT VARIANT 601 TUMORS FORMING EPITHELIAL NESTS, STRANDS, CORDS & DUCTS [PART B] 601 TRICHOADENOMA 604 TRICHOFOLLICULOMA (HAIR FOLLICLE NEVUS) 606 TRICHOBLASTOMA 606 TRICHOBLASTIC FIBROMA 606 TUMOR OF FOLLICULAR INFUNDIBULUM [PROBABLE CASE IS SS A1] 607 FIBROFOLLICULOMA 607 SYRINGOMA 608 AGGRESSIVE DIGITAL PAPILLARY ADENOMA/ADENOCARCINOMA 611 TUBULAR APOCRINE ADENOMA 611 ECCRINE POROCARCINOMA 616 ECCRINE ADENOCARCINOMA 616 MALIGNANT MIXED TUMOR 616 APOCRINE ADENOCARCINOMA 616 ADENOMYOEPITHELIOMA 616 TUMORS FORMING SHEETS & NODULES [PART C] 617 ECCRINE (APOCRINE) POROMA 617 HIDROACANTHOMA SIMPLEX 619 DERMAL DUCT TUMOR 620 POROID HIDRADENOMA [CONCEPTUALLY, HIDRADENOMA WITH ECCRINE DIFFERENTIATION] 620 ECCRINE (APOCRINE) POROMA [CLEAR CELL HIDRADENOMA] 620 TRICHODISCOMA 622 PERIFOLLICULAR FIBROMA [CE00-411, C/W PERIFOLLICULAR FIBROMA] 623 PROLIFERATING TRICHOLEMMAL TUMOR (PILAR TUMOR PROLIFERATING PILAR TUMOR PROLIFERATING TRICHOLEMMAL CYST MALHERBE TUMOR) 624 NODULAR HIDRADENOMA (SOLID-CYSTIC HIDRADENOMA CLEAR CELL HIDRADENOMA ECCRINE ACROSPIROMA CLEAR CELL MYOEPITHELIOMA) 625 CLASSIFICATION OF ECCRINE TUMORS ACCORDING TO HISTOGENESIS CLASSIFICATION OF ECCRINE TUMORS ACCORDING TO HISTOGENESIS [RAHBARI H.

26 6/25/2005 Dermatopathology Cribs for General 854/856 SYRINGOACANTHOMA. ACANTHOTIC LESIONS OF THE ACROSYRINGIUM. ARCH DERMATOL 1984; 120:751-56] 627 PILOMATRICOMA (PILOMATRIXOMA CALCIFYING EPITHELIOMA OF MALHERBE MALHERBE TUMOR) 627 ECCRINE SPIRADENOMA 628 SEBACEOUS PROLIFERATIONS AND NEOPLASMS 630 Sebaceous Hyperplasia 630 Surface Epithelioma with Sebaceous Differentiation [SESD] 630 Adenoma 631 Sebaceous Epithelioma 636 sebaceous carcinoma: 636 Key references for sebaceous growths: 637 ADNEXAL CARCINOMA 638 Eccrine Carcinoma 639 MALIGNANT ECCRINE TUMORS WITH BENIGN COUNTERPARTS 639 Malignant Mixed Tumor (Chondroid Syringoma) 639 Eccrine Porocarcinoma 639 Eccrine Spiradenocarcinoma 643 MALIGNANT ADNEXAL TUMORS WITHOUT BENIGN COUNTERPARTS 643 Eccrine Adenocarcinoma [also known as ductal eccrine adenocarcinoma ] 643 Mucinous Eccrine Carcinoma [SS , 57F, Lt eyelid, photo d] 644 Aggressive Digital Papillary Adenoma/Adenocarcinoma 645 APOCRINE 645 Apocrine Adenocarcinoma 645 Extramammary Paget s Disease (EMPD) 646 Mammary Paget s Disease VASCULAR NEOPLASMS & HAMARTOMAS 650 OUTLINE 652 DISCUSSION 655 I. REACTIVE TO INFECTIOUS AGENTS 655 A. Bacillary angiomatosis [BA Epithelioid Angiomatosis] 655 B. Verruga peruana (the vascular tumor in Oroya Fever [Carrion s Disease]) Bartonellosis 656 II. REACTIVE, POSSIBLY IMMUNE-MEDIATED 657 A. Reactive angioendotheliomatosis [Tappeiner-Pfleger Disease] 657 B. Glomeruloid hemangioma 657 III. REACTIVE, UNKNOWN ETIOLOGY 658 A. Intravascular papillary endothelial hyperplasia [Masson Lesion] 658 B. Pyogenic granuloma (lobular capillary hemangioma) [discussed below under benign tumors] 659 IV. VASCULAR MALFORMATIONS [INCLUDING TELANGIECTASIAS] 660 A. spider angioma [Nevus araneus] 660 B. Venous lake 660 C. Nevus flammeus (salmon patch, port-wine stain) 660 D. Angiokeratoma 661 E. Hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber disease) 662 F. Cutis Marmorata Telangiectoides 663

27 6/25/2005 Dermatopathology Cribs for General 855/856 V. BENIGN TUMORS 663 A. Capillary hemangioma 663 C. Tufted angioma (angioblastoma) 664 D. Cavernous hemangioma 665 Maffucci's syndrome and the blue rubber bleb nevus syndrome. 665 E. Pyogenic granuloma [PG] (lobular capillary hemangioma) 666 F. Epithelioid Hemangioma [EH] [see discussion of angiolymphoid hyperplasia with eosinophilia, below, sub G] 668 G. Angiolymphoid hyperplasia with eosinophilia (ALHE) [q.v. discussion of Epithelioid Hemangioma, above, F] 669 H. Angiomatosis [also known as diffuse angiomatosis ] 672 I. Targetoid hemosiderotic hemangioma (hobnail hemangioma) 673 J. Arteriovenous (venous) hemangioma (cirsoid aneurysm) (arteriovenous malformation AVM) 673 K. Microvenular hemangioma [microcapillary hemangioma] 674 L. Spindle cell hemangioendothelioma (Spindle cell hemangioma) 674 VI. LOW-GRADE MALIGNANT VASCULAR TUMORS 676 A. Kaposi's sarcoma [KS] Immunopathology of Kaposi s 683 B. Epithelioid hemangioendothelioma (EHE) [see discussion above, V.G & H, epithelioid hemangioma & ALHE] 684 C. Retiform hemangioendothelioma 685 D. Malignant endovascular papillary angioendothelioma (Dabska's tumor) 686 E. Kaposi-like infantile hemangioendothelioma [Kaposiform hemangioendothelioma; KHE] 687 F. Angiomatoid Malignant Fibrous Histiocytoma 688 VII. OVERTLY MALIGNANT VASCULAR TUMORS 689 A. Angiosarcoma 689 B. Epithelioid Angiosarcoma 692 VIII. LYMPHATIC VESSEL TUMORS 692 A. Lymphangiomas & 2. Cystic hygroma/cavernous lymphangioma Lymphangioma circumscriptum Progressive lymphangioma (benign lymphangioendothelioma) 695 IX. TUMORS OF PERITHELIAL AND GLOMUS CELLS 695 A. Glomus tumor A. VASCULAR OR APPARENTLY VASCULAR LESIONS MANIFESTING A SOLID GROWTH PATTERN EITHER FOCALLY OR AT SOME POINT IN THEIR EVOLUTION DIFFERENTIAL DIAGNOSTIC CONSIDERATIONS IN PUSTULAR, HYPERKERATOTIC AND SPONGIOTIC DERMATITIS OF THE PALMS AND SOLES CUTANEOUS LESIONS WITH DERMATOMAL DISTRIBUTION, DISTRIBUTION ALONG LINES OF BLASCHKO OR LINEAR DISTRIBUTION 722

28 6/25/2005 Dermatopathology Cribs for General 856/ SKIN AND SOFT TISSUE LESIONS POSITIVE FOR CD99 [MIC-2] AND CD34 AND BCL CD-99 POSITIVE TUMORS 724 CD34 POSITIVE TUMORS [CD34-POSITIVE] 729 CUTANEOUS/SOFT TISSUE TUMORS WHICH ARE POSITIVE FOR CD99 & CD SKIN & SOFT TISSUE TUMORS POS FO R BCL Immunohistochemical expression 732 References CUTANEOUS LYMPHOID (B&T-CELL) HYPERPLASIA [CLH] VS. CUTANEOUS B-CELL LYMPHOMA [CBCL] VS. CUTANEOUS T-CELL LYMPHOMA [CTCL] INFLAMMATORY DISEASES AFFECTING NAILS 737 INDEX 741

29 6/25/2005 Dermatopathology Cribs for General 502/856 rheumatoid neutrophilic dermatosis and Wegener s Granulomatosis may also show similar changes, but usually will have a significant population of neutrophils and even some eosinophils. I have also seen intense perivascular cuffing of small lymphocytes in association with a few neutrophils and focal lymphocytic vasculitis with eccrinotropism and a normalappearing epidermis in a case of long-standing Tinea [F01-930, our #CE01-781]. This lesion also had the wiry collagen transformation of the papillary dermal collagen without true lichen simplex chronicus. There were no plasma cells or eosinophils in the infiltrate. Acute Vulvar Vestibulitis PERIFOLLICULAR AND PERIADNEXAL MIXED CELL INFILTRATE WITH EOSINOPHILS Pruritic papular eruption of AIDS [J Am Acad Dermatol 1991; 24: Histology: 1) S & mid PV & perifollicular lymphohistiocytic inflammatory infiltrate + numerous eosinophils, 2) varying degrees of follicular damage such as spongiosis, folliculitis, 3) perieccrine and perineural lymphohistiocytic inflammatory infiltrate Photoallergic dermatitis and photoallergic contact dermatitis Allergic contact dermatitis sometimes Follicular eczema variant of atopic dermatitis Alopecia mucinosa, particularly that associated with the pilotropic variant of mycosis fungoides. May also have plasma cells. Follicular mucinosis, particularly that associated with the pilotropic variant of mycosis fungoides. May also have plasma cells & eosinophils. Cerroni L, Fink-Puches R, Back B, Kerl H. Follicular mucinosis: a critical reappraisal of clinicopathologic features and association with mycosis fungoides and Sezary syndrome. Arch Dermatol 2002;138(2): Flaig MJ, Cerroni L, Schuhmann K, et al. Follicular mycosis fungoides. A histopathologic analysis of nine cases. J Cutan Pathol 2001;28(10): Follicular mycosis fungoides without follicular mucinosis Monopoli A, Annessi G, Lombardo GA, Baliva G, Girolomoni G. Purely follicular mycosis fungoides without mucinosis: report of two cases with review of the literature. J Am Acad Dermatol 2003;48(3): Insect bite reaction [would not expect to be entirely peri-adnexal. Should also have an interstitial component.] Drug eruption Erythema chronicum migrans [Lyme borreliosis. Has plasma cells & eosinophils, but eosinophils are only around site of tick bite. Spirochetes demonstrable by Steiner or Warthin- Starry or Dieterle stain near basement membrane zone & around inflamed venules]. See: Berger B. Current Aspects of Lyme Disease & other B. burgdorfferi infections. Dermatol Clin 1997; 15: (Abst on file in EndNote). rheumatoid neutrophilic dermatosis and Wegener s Granulomatosis may also show similar changes, but usually will have a significant population of neutrophils and even some eosinophils Conditions in which inflammatory or Neoplastic Cells tend to line up along Epidermal Basement Membrane Zone. Cells line up along BMZ (put in for finding this in WORD) [see 106, granulocytic [phlegmonous] dermatitis 117, causes of increased dermal neutrophils 142, abundant karyorrhectic debris in dermis ]

30 6/25/2005 Dermatopathology Cribs for General 503/856 erythema multiforme [lymphocytes]. I have had cases of EM in which there was confluent epidermal necrosis in which apoptotic small lymphocytes could still be found lined up along the shadow of the destroyed BMZ. I have a photo of this [P (NF)] some interface drug reactions, both of the EM type, but also in less diffuse examples [basal lymphocyte tagging will be focal in this case]. Lymphocytes may tag the epidermal basal cells in scattered foci rather than all along the DEJ as in erythema multiforme. May also have karyorrhectic debris at the DEJ & even moving into the lower epidermis between the keratinocytes & associated with satellite cell necrosis. some cases of macular amyloidosis [lymphocytes and karyorrhectic debris] Lichen planus (and possibly BLK [YES. BLK can have this, see SS /A1. pictures are taken]) [lymphocytes] acute graft vs host reaction [lymphocytes with satellite cell necrosis] poikiloderma atrophicans vasculare [early Mycosis Fungoides, atypical lymphocytes]. In small plaque parapsoriasis (SPP) there may be slight lymphocyte exocytosis, but they do not line up along the DEJ. parapsoriasis en plaques [early Mycosis Fungoides, atypical lymphocytes. Note that in small plaque parapsoriasis you may see focal, slight intraepidermal exocytosis of small lymphocytes, but they do not line up along the DEJ or basal cell layer as in true early MF] [see 103, classification of parapsoriasis]. lymphocytes Thrombotic microangiopathies including: DIC, thrombotic thrombocytopenic purpura, coumarin necrosis vasculopathy [neutrophils & karyorrhexis] Gangrene and other vascular occlusive diseases. [neutrophils and karyorrhectic debris] Dermatitis herpetiformis [intact & fragmented neutrophils; discontinuous distribution as opposed to linear IgA dermatosis] Epidermolysis bullosa acquisita [EBA lymphocytes. (may also see neutrophils & karyorrhectic debris like DH occasionally in the neutrophil-rich variant of EBA)] The occasional case of bullous pemphigoid which may resemble dermatitis herpetiformis [neutrophils] Bullous pemphigoid, both the urticarial & bullous phases [eosinophils. See F04-810(GI). Photo taken. See also F (NC)] Acute bullous & nonbullous LE [karyorrhectic debris & some intact neutrophils] SLE may have subtle histopathologic findings including slight basal vacuolopathy, lymphocyte tagging of the basal layer of the epidermis and increased dermal mucin. [The Cutaneous Pathology of lupus erythymatosus: a review. J Cutan Pathol 2001;28;1-23; McCauliffe DP. Cutaneous Lupus Erythematosus. Sem Cutan Med Surg 2001;20:14-26] Linear IgA bullous dermatosis [LABD] [intact & fragmented neutrophils continuous distribution] Basal cell layer of ordinary Trichoepithelioma may have lymphocytes lined up among the palisaded outer layer of epithelial cells. Lymphocytes may infiltrate the basaloid cell nests as well. This can help differentiate TE from BCC on occasion. Occasional cases of lichen striatus [Gianotti R, Restano L, Grimalt R, et al.lichen striatus a chameleon: a histopathological and immunohistological study of 41 cases. J Cutan Pathol : 18-22] Herpes [pemphigoid] gestationis [eosinophils look for associated scattered necrotic epidermal keratinocytes] Pernio (chilblains) [lymphocytes]. There is idiopathic pernio & so-called chilblains lupus. The latter is differentiated from the idiopathic variety by the presence of interface vacuolopathy [it is important to mention this as either a positive or negative finding when you have a case of pernio] and fibrin deposition within reticular dermal blood vessels. Lupus pernio should also have increased dermal acid mucopolysaccharides demonstrable by the colloidal iron stain. In idiopathic pernio