Invisible Dermatoses. Dermal Diseases. Epidermal Diseases

Transcription

1 Invisible Dermatoses To our knowledge, Martin Brownstein and Asher Rabinowitz first used the term "invisible dermatoses."* Generations of dermatologists, however, have struggled with biopsy 3. specimens from diseased skin that appear to be normal under the microscope. Since normal skin is rarely ever biopsied in clinical practice, one must assume that some disease is present. Technical problems must be eliminated, such 4. as sampling errors where normal skin on an edge of the biopsy specimen has been sectioned and the diseased tissue has been left in paraffin. It is wise to check again to see if the clinician might have submitted normal skin (e.g., pruritus, resolved urticaria, patient insisting that normal spot is painful, and normal skin obtained for IF but submitted for H&E staining). At this point, one needs a strategy for studying skin that appears histologically normal, but must contain disease. We consider the following conditions: Epidermal Diseases 1. Tinea versicolor and fungal disease Check the stratum corneum for hyphae and do a PAS stain. 2. Porokeratosis-Porokeratosis may have lit- *Brownstein MH, Rabinowitz AD: The invisible dermatoses. J Am Acad Dermatol 8: , tle else besides a cornoid lamella. Multiple sections must be searched to find this structure (p. 176). Ichthyosis-Often the only clue to ichthyosis vulgaris is the absence of a granular layer that is associated with compact hyperkeratosis. In the absence of hyperkeratosis, this is an easy diagnosis to miss. Pigment changes-vitiligo looks almost normal, except that melanocytes are missing (as is melanin). Conditions that have increased melanin, but normal numbers of melanocytes (e.g., freckles and cafe au lait spots) may be mistaken for normal black skin. Dermal Diseases 1. Incontinence of pigment-melanin in the papillary dermis may be the only clue to a dermatitis that involved the epidermal-dermal junction (e.g., lichen planus or lupus erythematosus ). 2. Amorphous deposits in the papillae-macular amyloidosis can have very subtle deposits of amyloid in the dermal papillae; other forms of cutaneous amyloidosis may have deposition around blood vessels. Special stains for amyloid will help. 3. Mast cell infiltrates (p. 161)-Mastocytomas are easy to identy, but both urticaria pigmentosa and telangiectasia macularis eruptiva 209

2 210 perstans may have only slightly increased numbers of mast cells. Eosinophils, increased pigment, and increased vessels are adjunctive clues. 4. Dermal melanocytes-sometimes, the deposition of dermal spindle-shaped melanocytes in a blue nevus can be quite subtle. In the more diffuse dermal melanocytic conditions (e.g., Mongolian spot in the neonates), it often is impossible to find the melanocytes. 5. Argyria-A patient may be almost silverblack clinically with cutaneous silver deposits and still have only subtle grains of silver about dermal sweat ducts histologically. Always examine the basement membrane zone around sweat ducts in otherwise normal skin. 6. Urticaria-Urticarial lesions often may show only minimal edema with a sparse perivascular lymphocyte infiltrate. Sometimes, a resolving urticarial lesion will be normal or a true invisible dermatosis. 7. Connective tissue-connective tissue abnormalities can be very subtle; here, it often is necessary to compare normal and abnormal structures either by studying an ellipse whose Invisible Dermatoses long axis traverses the border between diseased and normal skin or by studying punch biopsy specimens from diseased and contralateral normal skin (the latter would then, by definition, be an invisible dermatosis if misfiled or transposed). Macular atrophy, or anetoderma, is defined by the absence of elastin with normal collagen; in atrophoderma, however, the dermis is simply reduced in thickness, but contains normal elastin and collagen. Both present as depressions; thus, a careful biopsy procedure, comparison with normal skin, and use of special stains all are required for an accurate diagnosis. In focal dermal hypoplasia, the dermis also is thinned, but to such an extent that the diagnosis is obvious. Connective tissue nevus (or the shagreen patch in tuberous sclerosis) has an excess of elastin, collagen, or both. Once again, only comparison within normal skin and use of special stains will allow a diagnosis. There are many other examples of invisible dermatoses; hopefully, however, these few disease entities will give the beginner a means of approaching the problem.

3 Further Readings Walter H. C. Burgdorf As mentioned in the introduction, this book was produced without references to help maintain its simple format. I hope that every reader will have access to at least one additional dermatopathology textbook and will consult it often; both for further information and for references. This annotated reading list is selective-not inclusive. Hopefully it provides an adequate introduction to the literature of derma topa thology. STANDARD TEXTBOOKS Lever WF, Schaumberg-Lever G: Histopathology of the Skin. JB Lippincott, Philadelphia, 1983, 848 pp. (Dr. Lever's book is the classic text with the best references. I cannot imagine studying a microscopic slide or writing about skin pathology without a copy at my side.) Pinkus H, Mehregan AH: A Guide to Dermatohistopathology. Appleton-Century Crofts, New York, 1981,591 pp. (If you canfind an older edition of this text, buy it. Dr. Pinkus was among the first to emphasize correlation of skin anatomy and disease, an embryologic approach to appendageal tumors, and pattern diagnosis. In later editions, his text has become more diffuse and encyclopedic.) OTHER BOOKS Ackerman AB: Histologic Diagnosis of Inflammatory Skin Diseases. Lea & Febiger, Philadelphia, 1978, 863 pp. (As mentioned on p. 57, Dr. Ackerman's book gives a sense of order to the befuddling world of inflammatory skin disorders. I highly commend both his approach and his book.) Ackerman AB, Niven J, Grant-Kels JM: Differential Diagnosis in Dermatopathology. Lea & Febiger, Philadelphia, 1982, 195 pp. (The format of this effort is unique. Dr. Ackerman and his coworkers contrast 45 pairs of difficult histologic diagnoses, such as Paget's disease versus Bowen's disease, with color pictures and lists of diagnostic criteria.) Enzinger FM, Weiss SW: Soft Tissue Tumors. The CV Mosby Co, St. Louis, 1983, 840 pp. (Dr. Enzinger and Dr. Weiss have produced a masterpiece; readable, but unquestionably authoritative. Dermal proliferations, whether neural, muscular, vascular, or fibroblastic, are reviewed in depth; but, in a practical fashion.) McGovern VJ: Melanoma: Histological Diagnosis and Prognosis. Raven Press, New York, 1983, 197 pp. Roses DF, Harris MN, Ackerman AB: Diagnosis and Management of Cutaneous Malignant Melanoma. WB Saunders, Philadelphia, 1983, 304 pp. (Malignant melanoma is, at once, the most important single topic in dermatology and a most difficult subject to adequately cover in an introductory textbook. These two new 211

4 212 books have been most helpful to me in trying to keep abreast of this crucial area.) PERODICALS No textbook can be up to date; something is always new in the literature. Two journals are devoted specifically to dermatopathology: American Journal of Dermatopathology Journal of Cutaneous Pathology These two journals, however, have not captured the market as far as quality skin pathology articles. Many outstanding dermatopath- Further Readings ology papers appear in the following journals: American Journal of Surgical Pathology Archives of Dermatology British Journal of Dermatology Cancer Histopathology Journal of the American Academy of Dermatology Once again, other valuable dermatopathology articles appear outside of this short list; however, if you read the above journals, you will rarely be too far behind in studying skin.

5 Glossary This glossary is highly restricted; it only includes those dermatopathologic terms that are used in the histologic descriptions in this manual. Many important expressions have been omitted simply because of the limited size of the text. Furthermore, no attempt has been made to define normal structures or diseases; these subjects are listed in the index. Abscess: Accumulation of neutrophils. Acantholysis: Loss of adhesion between epidermal cells. Acanthosis: Thickening of epidermis because of increased number of keratinocytes (see Hypertrophy). Atrophy: Condition of being flattened or thinned; most often refers to a thinned layer, such as epidermis or dermis. Atypia: Cytologic abnormality of cells, with abnormal irregularly shaped nuclei and mitoses; suggesting a malignant change. Ballooning degeneration: Epidermal change in viral blisters, where marked intracellular edema destroys the intercellular connections. Basaloid: Resembling cells of the basal layer. Basket-weave hyperkeratosis: When the normal horny layer pattern of retained cell walls and "lost" cytoplasm is exaggerated, the wall remnants resemble basket-weaving. Basophilic: Bluish color resembling basal cells' color (on hematoxylin and eosin stain). Basophilic degeneration: Actinic degeneration of collagen; the damaged collagen stains bluish, rather than the normal reddish tint. Buckshot scatter: Random distribution of melanocytes through epidermis in malignant melanoma. Cartwheel pattern: Spindle-shaped tumors may be arranged so that the elongated cells radiate from a central point like a cartwheel. Caseation necrosis: Total necrosis, initially described in tuberculosis; histologically, one sees no remnants of cell structures, just necrotic material. Civatte body: Degenerated keratinocyte, which appears homogeneous and eosinophilic; common in lichen planus. Collarette: A little collar; refers to a peripheral process, such as scale about a lesion or an epidermal reaction about a tumor, or such as the epidermis encompassing the metastatic malignant melanoma (p. 138). Colloid body: See Civatte body. Cornoid lamella: Parakeratotic column in porokeratosis. Corps ronds: Dyskeratotic acantholytic cell, with a central basophilic nucleus, clear halo, and peripheral keratin shell. Cuffing: Accumulation of cells (usually lymphocytes) about a vessel. Cytolysis: Destruction of cells, as in viral destruction of epidermis. Desmoplasia: Proliferation of dermal fibrous elements, as in desmoplastic malignant melanoma. Dirty feet: Accumulation of melanin at base of rete ridges in actinic lentigo. 213

6 214 Dyskeratosis: Abnormal, usually premature, keratinization of epidermal cells, which lead to individual cell keratinization rather than orderly formation of stratum corneum; can be either acantholytic (as in Darier's disease) or neoplastic (as in Bowen's disease). Dysplasia: Tissue change with disordered growth that includes both cytologic abnormalities (atypia) and pattern abnormalities. Edema: Tissue swelling from leakage of fluid out of vessels. Entrapment of collagen: Change at periphery of dermatofibroma (Fig. 174); probably does not involve any "trapping," but small fragments of normal collagen appear to be encircled by abnormal collagen. Eosinophilic: Reddish color, as the granules of an eosinophil (in hematoxylin and eosin stain). Epidermotropism: Migration of cells into the epidermis without associated spongiosis or other signs of inflammation. Epidermolysis: Separation of epidermis from dermis at epidermal-dermal junction; now somewhat archaic, since the junction has become so complex. Epidermolytic hyperkeratosis: Peculiar granular degeneration of epidermis, which is seen in a variety of congenital and acquired conditions. Exocytosis: Migration of cells into the epidermis with associated spongiosis. Fibrinoid degeneration: Collagen or vessel wall acquires a bright eosinophilic homogeneous appearance. Fibrosis: Proliferation of dermal fibrous elements. Freundenthal's lacuna: Subepidermal space (or lacuna) in actinic keratosis. Grain: Dyskeratotic-acantholytic cell with condensed keratin. Grenz zone: Zone of normal dermis between dermal infiltrate and epidermis. Ground-glass cytoplasm: Eosinophilic amorphous change in cytoplasm of epidermal cells (as in keratoacanthoma). Glossary Horn pseudocyst: Epidermal invagination in seborrheic keratosis. Hydropic degeneration: Damage to the cells of the basal layer, which produces tiny spaces or vacuoles in the cells. Hypergranulosis: Thickening of the stratum granulosum (granular layer). Hyperkeratosis: Thickening of the stratum corneum. Hypertrophy: Literally, excessive growthin contrast to acanthosis; hypertrophy suggests an epidermal thickening by an increase in cell size, not cell number. Hypoplasia: Thinning because of a decrease in cell number. Incontinence of pigment: Dropping of melanin into the dermis because of inflammation at the epidermal-dermal junction. Indian filing: Distribution of infiltrating tumor cells between strands of collagen. In situ: Confined to the epidermis. Kamino body: Eosinophilic globules in epidermis of Spitz nevi. Kogoj's pustule: See spongiform pustule of Kogoj. Lentiginous: Resembling a lentigo with elongated rete ridges. Leukocytoclasia: Destruction of neutrophils to leave nuclear fragments and dust; seen in vasculitis. Lichenoid: Resembling lichen planus with a band-like infiltrate at the epidermal-dermal junction. Metachromasia: Phenomenon in which material stains with a color different from that of the dye used, as with mast cell granules that stain purple with the blue Giemsa stain. Microabscess: Tiny abscess (see Munro and Pautrier). Monomorphism: Uniformity of cell types, as in an infiltrate composed solely of small lymphocytes. Mucin: General term for amorphous glycoproteins. Dermal mucins are basophilic and represent variations in ground substance. Epidermal mucins are secretory products (e.g., in the ductal tumors of Paget's disease).

7 Glossary Munro microabscess: Accumulation of neutrophils in parakeratotic stratum corneum of psoriasis. Necrobiosis: Degenerative change in collagen (literally in a condition of life and death), which is best seen in granuloma annula:e. Necrolysis: Separation of tissue caused by cell death. Necrosis: Cell or tissue death. Nuclear dust: See leukocytoclasia. Pagetoid: Resembling Paget's disease, with clear cells distributed throughout the epidermis; also seen in Bowen's disease and malignant melanoma. Papilloma: Lesion that resembles a nipple in the sense of having many tiny undulations; histologically, papillomas show papillomatosis. Papillomatosis: Elongation of dermal papillae, with associated hyperkeratosis. Parakeratosis: Retention of nuclei in the stratum corneum. Pautrier microabscess: Atypical cerebriform lymphocytes clustered in the epidermis without spongiosis in mycosis fungoides. Perivasculitis: Accumulation of cells (usually lymphocytes) about vessels without vessel wall damage. Pleomorphism: Variation in the appearance of cells of the same type. Polymorphism: Variation in types of cells. Porokeratosis: Literally means keratinization about pores, but has come to mean disorders of keratinization with cornoid lamellae. 215 Pseudoepitheliomatous hyperplasia: Downward reactive epidermal proliferation that mimics squamous cell carcinoma in any chronic inflammation and at the edge of chronic ulcers. Psoriasiform: Resembling psoriasis with elongation of rete ridges. Reticular degeneration: Epidermal change in viral blisters in which only cell walls are left in multilocular blisters. Also may be seen in very severe spongiosis. Saw-toothing: Notching of the lower epidermis in lichen planus. Sclerosis: Proliferation of dermal fibrous elements. Solar elastosis: See basophilic degeneration. Spongiform pustule of Kogoj: Large neutrophilic pustule in pustular psoriasis; larger and lower in the epidermis than Munro microa bscess. Spongiosis: Intercellular edema in epidermis; hallmark of acute inflammation. Squirting papilla: Neutrophils in flattened epidermal plate and overlying stratum corneum in psoriasis. Storiform pattern: Spindle-shaped tumors may be arranged so that the elongated cells intertwine to resemble weaving. Vacuolar degeneration: See hydropic degeneration.. Vasculitis: Inflammation damaging a blood vessel; in the skin, usually associated with leukocytoclasia.

8 Index All the major concepts in the text are included in the index. Every disease reference is included, including all those places where a given disease process is mentioned in a differential diagnosis. The major page reference where a disease is illustrated is signified by italic type. No glossary terms are indexed. Individual special stains are not indexed; they are cross-referenced on page 27. Acanthosis nigricans, 39, 146 Acral lentinginous malignant melanoma, 13 7 Acrokeratosis verruciformis, 39 Acrospiroma, eccrine, 159 Actinic degeneration, keratosis, 39, 93,141, Actinomycosis, 46 Adenoma sebaceum, 151 AIDS, Anchoring fibrils, Angiokeratoma, 195 Angioma, Angiosarcoma, 200 Apocrine gland, 8-9 hidrocystoma, 160 Arthropod bite, 56, Atrophy, Bacterid, pustular, 60 Balanitis xerotica obliterans, 97 Basal cell carcinoma, see carcinoma Basal lamina, Basal layer, 5-6 Basement membrane zone, 11-12, Biopsy specimen fixation, Candidiasis, 44, Carcinoma, basal cell, 40, 157, nodular, morpheaform, pigmented, 182 superficial, Carcinoma, squamous cell in situ, invasive, Cherry angioma, Clark's levels, 130 Clear cell hidradenoma, 159 Clear cells, epidermal, 177 Collagen, Comma tails, 154 Compound nevus, Condyloma acuminatum, 42-43, 149 Congenital nevus, 122 Cornoid lamella, 176 Corps rond, 143 Crust, 23 Cutaneous horn, Cylindroma, 156 Cyst, 21-22, epidermoid, pilar, Cytology, obtaining, 25 Darier's disease, 83, processing, 26 Decapitation secretion, 9 Blister, Dermal duct tumor, 157 Blue nevus, 128 Dermatofibroma, , 128 Bowenoid papulosis, 42 Dermatofibrosarcoma Bowen's disease, 149,172, protuberans, Breslow's depths, 130 Dermatitis Bulla, acute, Bullous diseases, chronic, immunofluoresence, herpetiformis, mechanisms, 81 interface, 15-16, table, 82 lichenoid, Bullous pemphigoid, 76, seborrheic, 57 Dermatomyositis, 95 Dermatophytes,54-55 Dermatoses classification, 57 invisible, lichenoid, psoriasiform, Dermatosis, transient acantholytic, 83, 143, 144 Dermis, embryology, 3-4 pathology, structure, Desmosome, 6 Dyskeratoma, warty, 143 Dyskeratosis, 16, Dysplasia, 16 Dysplastic nevus, Eccrine gland, 9-10 tumors, acrospiroma, 159 clear cell hidradenoma, 159 dermal duct tumor, 157 hidradenoma, clear cell, 159 hidrocystoma, 160 poroma, 157 spiradenoma, 158 Elastin, 13 Electron microscopy, 28 Embryology, 3-4 Eosinophil, 18 Epidermal-dermal junction, 11-12, Epidermal nevus, Epidermis, embryology, 3-4 pathology, structure, 5-11 Epidermoid cyst, Epidermolysis bullosa,

9 218 Epidermolytic hyperkeratosis, 140, 174 Erosion, Erythema elevatum diutinum, 105 Erythema multiforme, 76-77,91 Erythema nodosum, 75 Erythroplasia, 177 Excoriation, Fibrils, anchoring, Fibroblast, 20 Fibroepithelioma, Pinkus, 149, 185 Fibrosarcoma, 108 Fixation, Fissure, Flat wart, Fordyce spot, 8 Foreign body giant cell, granuloma, 100, Freudenthal's lacunae, 172, 175 Fungal diseases, Genital wart, Giant cell, foreign body, Langhans, 19-20, nevus, 121 Touton, 19-20, II 0-1 II viral, Gland apocrine, 8-9 eccrine, 9-10 sebaceous, 8 Glomus tumor, 161,197, Grain, 143 Granular layer, 6 Granuloma, annulare, 40, faciale, 105 foreign body, 100, pyogenic, tuberculoid,47-48 Ground substance, 13 Hailey-Hailey disease, 83, 143, Hair destruction, 66-67, structure, 7-8 Halo nevus, 122 Hemangioma, Hemangiopericytoma, 197 Herpes virus, Hidradenoma, clear cell, 159 Hidmcystoma, 160 apocrine, 160 eccrine, 160 Histiocyte, 18 Histiocytoma, 49, , 112 Histiocytosis X, Hive, 22 Horn pseudocyst, 147 Horny layer, 6 Hypertrophy, 24. Immunofiuoresence, Immunohistochemistry, Immunoperoxidase,27-28, III Impetigo, 44-45, 59, 78 Indian filing, Interface dermatitis, 15-16,62-63 Intradermal nevus, II Invisible dermatoses, Irritated seborrheic keratosis, Junctional nevus, Juvenile xanthogranuloma, I lo- 1lI,123 Kamino body, 123 Kaposi's sarcoma, Keratin, 6 Keratoacanthoma, Keratohyalin, 6 Keratosis actinic, 39, 141, hypertrophic actinic, 189 lichenoid actinic, 67, 93, 172 lichenoid, 67 seborrheic, 39, 40, 42, 141, ,157,185 irritated seborrheic, stucco, 39 Kogoj pustule, 59 Lamina lucida, Laminin, Langerhans cell, 10-11,207 Langhans giant cell, 19-20,47-48 Leiomyoma, Lentigo actinic, 117 maligna, 117 simple, 116 Lentigo maligna melanoma, Leprosy, lepromatous, 49-50, 112 tuberculoid, 49-51, 100 LEOPARD syndrome, 116 Leukemia, Leukocyte, 18 Leukocytoclastic vasculitis, 61, 73, 76 Lichen, nitidus, 67 planus, 66-67, 91,93 hypertrophic, 72 Index sclerosus et atrophicus, 91, simplex chronicus, 72 Lichenification, 24 Lichenoid actinic keratosis, 67, 93, 172 dermatitis, keratosis, 67 Lupus band test, Lupus erythematosus, 79, 92-95, 102 discoid, hypertrophic, 72 subacute, 95 systemic, 95 Lupus vulgaris, Lymphangioma, 196 Lymphocyte, 18 Lymphocytic infiltrate, Lymphocytic perivasculitis, 61, 70-71, 73, 76, 87 Lymphoid hyperplasia, Lymphoma, malignant, differential diagnosis, 79 epithelioid, 50 mycosis fungoides, T-cell, Lymphomatoid papulosis, 61 Macule, 22 Malherbe tumor, 155 Mast cell infiltrate, structure, 20 Mastocytoma, 110, 123, , 197 Melanocyte, 10, Melanoma, malignant acral lentiginous, 137 depths, 130 general aspects, histologic criteria, 131 lentigo maligna, 117, metastatic, nodular, superficial spreading, , 177 survival, 130 Merkel cell, 11, 13 Mesenchyme, 3 Metastatic tumors malignant melanoma, other, Microfibrils, Molluscum contagiosum, Monocyte, 18 Morphea, 95-96, 97 Munro microabscess, 57, 59 Muscles, 14 Mycosis fungoides, 62-63,

10 Index 219 Necrobiosis, 99 Necrobiosis lipoidica diabeticorum, 99 Necrolysis, toxic epidermal, Nerves, 13 Neural nevus, 168 Neurilemmoma, 169 Neurofibroma, Neutrophil, 18 Nevus, epidermal, inflammatory, 140 Jadassohn, , 151 sebaceous, , 151 Nevus, meianocytic, , 168 blue, 128 compound, congenital, 122 dysplastic, halo, 122 intradermal, junctional, neural,168 recurrent, 125 spindle and epithelioid, Spitz, 110, Nodular malignant melanoma, Nodule, Paget's disease, 177, Painful tumors, 163 Palmar-plantar pustulosis, 60 Panniculitis, 75 Papilloma, 39 Papilloma viruses, Papule, Papulosis, Bowenoid, 42 lymphomatoid,61 Parapsoriasis, 57, guttate, 62 interface, Patch,22 Pautrier microabscess, Pemphigoid antigen, Pemphigoid, bullous, 76, Pemphigus, 44,82-86, 143, 144 foliaceus, 86, 144 vegetans, 85 vulgaris, Perivasculitis, lymphocytic, 61, 70-71, 73, 76, 87 Peutz-J eghers syndrome, 116 Phagocyte, 18 Pilar cyst, Pilomatricoma, 155 Pinkus tumor, 149,185 Pityriasis lichenoides chronica, 62, 64 lichenoides et varioliformis acuta, 52, 61, 64, 73 rosea, 61, Plane wart, Plaque, 21 Plasma cell, 18 Polarization, 104 Polyarteritis nodosa, 74 Polymorphonuclear leukocyte, 18 Porokeratosis, 140, 176 Poroma, eccrine, 157 Porphyria cutanea tarda, 91 Port wine stain, Prickle cell layer, 6 Pseudocyst, horn, 147 Psoriasis, 52, 57-58, 64 pustular, 44, 59 Pustular bacterid, 60 Pustule, Pustulosis palmar-plantar, 60 sub corneal, 44, 59 Pyogenic granuloma, Recurrent nevus, 125 Rheumatoid nodule, 99 Rosacea, 102 Sarcoidosis, 40, 50, Sarcoma, Kaposi's, Scabies, 56 Scalded skin, staphylococcal, 44, 78,86 Scale, 23 Scar, Scleredema, 95 Scleroderma, Scleromyxedema, 95 Sclerosis, 24 Sebaceous gland, 8 hyperplasia, 151 n e v , u ~ 151 Seborrheic dermatis, 57 Seborrheic keratosis, 39, 40, 42, 141, ,157 irritated, Senile sebaceous hyperplasia, 151 Sezary cell, Shadow cell, 155 Skin tag, Special stains, Spindle and epithelioid nevus, Spiradenoma, eccrine, 158 Spitz nevus, Stains, special, Staphylococcal scalded skin syndrome, 44, 78, 86 Stewart-Treves syndrome, 200 Stratum, basale, 5-6 corneum, 6 granulosum, 6 lucidum,6 spinosum,6 Strawberry hemangioma, Stucco keratosis, 39 Subcorneal pustulosis, 44, 59 Sulfur granule, 46 Superficial spreading malignant melanoma, , 177 Sweet syndrome, 105 Syphilis, Syringoma, 40, 154 T-cell lymphoma, Telangiectasia macularis eruptiva et perstans, 161 Tonofibril, 6 Tonofilament, 6 Touton giant cell, 20, 111 Toxic epidermal necrolysis, Transient acantholytic dermatosis, 83, 143, 144 Tuberculosis, Tzanck smear, Ulcer, Urticaria, 22 Urticaria pigmentosa, 161 Varicella-zoster virus, Vasculitis, leukocytoclastic, 61, 73,76 Verruca, 38-43, 141 vulgaris, Vesicle, Vessels, Viral diseases, herpes, molluscum contagiosum, verruca, warts, Von Recklinghausen's disease, 166 Wart, common, flat, genital, plane, Warty dyskeratoma, 143 Xanthelasma, Xanthogranuloma, juvenile, , 123 Xanthoma, 49, 106, verruciform, 112