Dermatopathology

I. Inflammatory Dermatitis A. Spongiotic Dermatitis * Atopic Dermatitis * Seborrheic Dermatitis * Allergic Contact Dermatitis * Dyshidrotic Eczema * Stasis Dermatitis * Spongiotic Drug Reaction * Insect Bite Reaction * Incontinentia Pigmenti * Pityriasis Rosea * Photosensitive (Phototoxic/Photoallergic) Dermatitis B. Psoriasiform and Pustular Dermatitis * Psoriasis * Reiter's Syndrome * Pityriasis Rubra Pilaris * Subcorneal Pustular Dermatosis * Acute Generalized Exanthematous Pustulosis * Transient Neonatal Pustular Melanosis * Lichen Simplex Chronicus/Prurigo Nodularis * Inflammatory Linear Verrucous Epidermal Nevus C. Interface Dermatitis * Erythema Multiforme * Toxic Epidermal Necrolysis/Stevens-Johnson Syndrome * Lupus Erythematosus * Dermatomyositis * Graft-Versus-Host Disease * Interface Dermatitis of HIV Infection * Pityriasis Lichenoides D. Lichenoid Dermatitis * Lichen Planus * Lichenoid Drug Eruption * Fixed Drug Eruption * Lichen Striatus * Lichen Nitidus * Ashy Dermatosis (Erythema Dyschromicum Migrans) * Lichenoid Keratosis E. Acantholytic Disorders * Pemphigus Foliaceus * Pemphigus Erythematosus * IgA Pemphigus * Pemphigus Vulgaris * Pemphigus Vegetans * Paraneoplastic Pemphigus * Darier's Disease * Hailey-Hailey Disease (Familial Benign Pemphigus) * Grover's Disease (Transient Acantholytic Dermatosis) F. Subepidermal Vesicular Dermatitis * Bullous Pemphigoid * Herpes Gestationis * Cicatricial Pemphigoid * Epidermolysis Bullosa Acquisita * Epidermolysis Bullosa Congenita * Dermatitis Herpetiformis * Linear IgA Disease * Porphyria Cutanea Tarda * Pseudoporphyria G. Granulomatous Dermatitis * Granuloma Annulare * Necrobiosis Lipoidica * Rheumatoid Nodule * Palisaded Neutrophilic Granulomatous Dermatitis (Interstitial Granulomatous Dermatitis with Arthritis) * Necrobiotic Xanthogranuloma * Sarcoidosis * Cutaneous Crohn's Disease * Foreign Body Reaction H. Superficial and Superficial and Deep Perivascular Dermatitis * Erythema Annulare Centrifigum * Urticaria * Polymorphous Light Eruption I. Folliculitis, Perifolliculitis, and Inflammation of the Sweat Apparatus * Acne Vulgaris * Rosacea * Hidradenitis Suppurativa * Acne Agminata * Folliculitis * Eosinophilic Folliculitis * Neutrophilic Eccrine Hidradenitis * Acne Keloidalis Nuchae J. Alopecia * Alopecia Areata * Androgenetic Alopecia * Dissecting Cellulitis * Follicular Degeneration Syndrome * Folliculitis Decalvans * Lichen Planopilaris and Frontal Fibrosing Alopecia K. Vasculitis and Vasculopathy * Leukocytoclastic Vasculitis * Henoch-Schonlein Purpura (HSP) * Urticarial Vasculitis * Granuloma Faciale * Erythema Elevatum Diutinum * Polyarteritis Nodosa * Wegener's Granulomatosis * Churg-Strauss Syndrome (Allergic Granulomatosis with Angiitis) * Disseminated Intravascular Coagulation * Cryoglobulinemia * Antiphospholipid Antibody Syndrome * Coumadin Necrosis * Cholesterol Crystal Embolism * Giant Cell Arteritis * Atrophie Blanche * Lymphocytic Vasculitis * Perniosis * Degos Disease * Pigmented Purpura L. Fibrosing/Sclerosing Dermatitis * Morphea * Scleroderma * Lichen Sclerosus * Nephrogenic Systemic Fibrosis (Nephrogenic Fibrosing Dermopathy) * Radiation Dermatitis M. Panniculitis * Erythema Nodosum * Alpha-1 Antitrypsin Deficiency Associated Panniculitis * Pancreatic Panniculitis * Subcutaneous Fat Necrosis of the Newborn * Nodular Vasculitis * Lupus Profundus * Factitial and Traumatic Fat Necrosis * Lipodermatosclerosis (Sclerosing Panniculitis) * Infective Panniculitis N. Other Inflammatory Dermatoses * Sweet's Syndrome * Pyoderma Gangrenosum * Behcet's Disease * Eosinophilic Cellulitis (Wells' Syndrome) * Eosinophilic Fasciitis * Zoon's Balanitis O. Disorders of Keratinization * Ichthyosis Vulgaris * Sex-Linked Ichthyosis * Lamellar Ichthyosis * Congenital Bullous Ichthyosiform Erythroderma * Palmoplantar Keratoderma * Porokeratosis * Axillary Granular Parakeratosis II. Infectious Dermatitis A. Viral Infections * Verruca Vulgaris * Verruca Plantaris (Plantar Wart) * Verruca Plana (Plane Wart) * Condyloma Accuminatum * Molluscum Contagiosum * Herpes Simplex * Varicella-Zoster Virus * Orf (Echthyma Contagiosum) B. Bacterial Infections * Impetigo * Staphylococcal Scalded Skin Syndrome * Necrotizing Fasciitis * Ecthyma * Bacillary Angiomatosis * Actinomycosis * Granuloma Inguinale * Anthrax * Corynebacterial infections * Lyme Disease * Syphilis * Lupus Vulgaris * Atypical Mycobacterial Infections * Leprosy C. Fungal Infections * Dermatophytosis * Tinea Versicolor * Candidiasis * Pityrosporum Folliculitis * Mycetoma * North American Blastomycosis * Histoplasmosis * Cryptococcosis * Coccidiodomycosis * Paracoccidiodomycosis (South American Blastomycosis) * Chromoblastomycosis (Chromocycosis) * Phaeohyphomycosis * Sporotrichosis * Aspergillosis * Zygomycosis D. Other Infections * Protothecosis * Rhinosporidiosis * Leishmaniasis * Amoebiasis Cutis * Onchocerciasis * Schistosomiasis * Scabies * Tungiasis III. Non-Inflammatory Dermatoses A. Metabolic and Degenerative Disorders * Necrolytic Migratory Erythema * Acrodermatitis Enteropathica * Cutaneous Amyloidosis * Adult Colloid Milium * Juvenile Colloid Milium * Gout * Lichen Myxedematosus/Scleromyxedema * Scleredema (Buschke) * Pretibial Myxedema * Follicular Mucinosis * Calcinosis Cutis * Calciphylaxis * Chondrodermatitis Nodularis Helicis B. Diseases of Collagen and Elastic Tissue * Pseudoxanthoma Elasticum * Elastosis Perforans Serpiginosa * Reactive Perforating Collagenosis * Kyrle's Disease (Hyperkeratosis Follicularis et Parafollicularis in Cutem Penetrans) C. Disorders of Pigmentation * Vitilgo * Drug-Induced Pigmentation IV. Neoplasms A. Cysts and Pseudocysts * Dilated Pore of Winer * Epidermoid Cyst * Pilar Cyst * Proliferating Pilar Tumor * Steatocystoma * Eruptive Vellus Hair Cyst * Hidrocystoma * Cutaneous Ciliated Cyst * Dermoid Cyst * Digital Myxoid Cyst B. Melanocytic Neoplasms * Ephelis * Lentigo * Ink Spot Lentigo * Labial Melanotic Macule * Melanocytic Nevus * Acral Nevus * Congenital Melanocytic Nevus * Halo Nevus * Balloon Cell Nevus * Recurrent (Persistent) Nevus (Pseudomelanoma) * Atypical Genital (Milk-Line, Flexural) Nevus (Nevus of Special Anatomic Sites) * Dysplastic Nevus * Spitz Nevus * Pigmented Spindle Cell Nevus (Reed Nevus) * Nevus of Ota (Nevus Fusoceruleus Ophthalmomaxillaris) and Nevus of Ito (Nevus Fusoceruleus Acromioclavicularis) * Blue Nevus * Combined Nevus * Deep Penetrating Nevus * Melanoma C. Keratinocytic Neoplasms * Epidermal Nevus * Seborrheic Keratosis * Inverted Follicular Keratosis * Stucco Keratosis * Borst-Jadasshon phenomenon * Large Cell Acanthoma * Acantholytic Acanthoma * Warty Dyskeratoma * Clear Cell Acanthoma * Actinic Keratosis * Squamous Cell Carcinoma * Squamous Cell Carcinoma In Situ * Keratoacanthoma * Verrucous Carcinoma * Basal Cell Carcinoma D. Follicular Neoplasms * Trichoepithelioma * Desmoplastic Trichoepithelioma * Trichilemmoma * Desmoplastic Trichilemmoma * Tumor of the Follicular Infundibulum (Infundibuloma) * Pilar Sheath Acanthoma * Basaloid Follicular Hamartoma * Trichoblastoma * Trichofolliculoma * Pilomatrixoma * Lymphadenoma Cutis * Trichilemmal Carcinoma * Matrical Carcinoma (Pilomatrix Carcinoma, Malignant Pilomatrixoma) E. Sebaceous Neoplasms * Nevus Sebaceus of Jadasshon (Organoid Nevus) * Sebaceous Hyperplasia * Sebaceous Adenoma * Sebaceoma * Sebaceous Carcinoma F. Eccrine/Apocrine Neoplasms * Poroma * Dermal Duct Tumor * Eccrine Syringofibroadenoma (Acrosyringeal Nevus) * Syringoma * Nodular Hidradenoma * Chondroid Syringoma (Mixed Tumor) * Eccrine Spiradenoma * Cylindroma * Syringocystadenoma Papilliferum * Hidradenoma Papilliferum * Tubular Apocrine Adenoma (Papillary Tubular Adenoma) * Papillary Eccrine Adenoma * Microcystic Adnexal Carcinoma * Adenoid Cystic Carcinoma * Eccrine Porocarcinoma * Primary Cutaneous Mucinous Carcinoma * Hidradenocarcinoma (Malignant Acrospiroma, Clear Cell Hidradenocarcinoma) * Eccrine Ductal Carcinoma * Aggressive Digital Papillary Adenocarcinoma * Apocrine Carcinoma G. Fibrous, Fibrohistiocytic, and Myofibroblastic Neoplasms * Hypertrophic Scar * Keloid * Fibrous Papule * Acrochordon (Fibroepithelial Polyp, Skin Tag) * Acquired Digital Fibrokeratoma * Superficial Angiomyxoma * Palmar Fibromatosis (Dupuytren's Contracture) * Nodular Fasciitis * Elastofibroma * Fibroma of Tendon Sheath * Giant Cell Tumor of Tendon Sheath * Inclusion Body Fibromatosis (Infantile Digital Fibromatosis) * Fibrous Hamartoma of Infancy * Sclerotic Fibroma (Storiform Collagenoma) * Infantile Myofibromatosis and Solitary Myofibroma * Myoepithelioma * Solitary Fibrous Tumor * Dermatofibroma (Benign Fibrous Histiocytoma) * Cellular Fibrous Histiocytoma * Atypical Fibrous Histiocytoma * Dermatomyofibroma * Dermatofibrosarcoma Protuberans (DFSP) * Giant Cell Fibroblastoma * Atypical Fibroxanthoma * Superficial Malignant Fibrous Histiocytoma (Superficial Pleomorphic Sarcoma-NOS) * Epithelioid Sarcoma H. Vascular Neoplasms * Intravascular Papillary Endothelial Hyperplasia (Masson's Tumor) * Lobular Capillary Hemangioma (Pyogenic Granuloma) * Port-Wine Stain * Infantile Hemangioma (Strawberry Nevus, Juvenile Hemangioma, Infantile Hemangioendotheioma) * Cavernous Hemangioma * Arteriovenous Hemangioma (Arteriovenous Malformation, Cirsoid Aneurysm) * Cherry Hemangioma (Senile Hemangioma, Campbell de Morgan Spot) * Angiokeratoma * Hobnail Hemangioma (Targetoid Hemosiderotic Hemangioma) * Spindle Cell Hemangioma * Multinucleate Cell Angiohistocytoma * Epitheliod Hemangioma (Angiolymphoid Hyperplasia with Eosinophilia) * Reactive Angioendotheliomatosis * Lymphangioma Circumscriptum * Glomus Tumor/Glomangioma * Myopericytoma * Epithelioid Hemangioendothelioma * Kaposi's Sarcoma * Cutaneous Angiosarcoma * Epithelioid Angiosarcoma I. Neural-Neuroendocrine Neoplasms * Traumatic Neuroma * Morton's Neuroma (Metatarsalgia) * Neurofibroma * Schwannoma (Neurilemmoma) * Palisaded Encapsulated Neuroma (Solitary Circumscribed Neuroma) * Granular Cell Tumor * Neurothekeoma (Myxoid Neurothekeoma, Dermal Nerve Sheath Myxoma) * Cellular Neurothekeoma * Perineurioma * Nasal Glioma * Malignant Peripheral Nerve Sheath Tumor (Neurofibrosarcoma, Malignant Schwannoma) * Merkel Cell Carcinoma J. Muscular Neoplasms * Leiomyoma and Angioleiomyoma * Leiomyosarcoma K. Adipose, Osseous, and Cartilaginous Neoplasms * Lipoma * Angiolipoma * Spindle Cell Lipoma * Pleomorphic Lipoma * Liposarcoma * Osteoma Cutis * Soft Tissue Chondroma L. T-Cell (and NK/T-Cell) Neoplasms * T-Cell Pseudolymphoma * Chronic Actinic Dermatitis (Actinic Reticuloid) * Mycosis Fungoides * Sezary Syndrome * Pagetoid Reticulosis * Granulomatous Slack Skin * Primary Cutaneous CD8-Positive Epidermotropic Cytotoxic T-Cell Lymphoma * Lymphomatoid Papulosis * Anaplastic Large Cell Lymphoma * Subcutaneous Panniculitis-Like T-Cell Lymphoma * Adult T-Cell Leukemia/Lymphoma (ATLL) * Extranodal NK/T-Cell Lymphoma, Nasal Type * Gamma/Delta T-Cell Lymphoma M. B-Cell Neoplasms * B-Cell Pseudolymphoma (Cutaneous Lymphoid Hyperplasia) * Primary Cutaneous Marginal Zone Lymphoma (MALT) * Follicle Center Cell Lymphoma (FCCL) * Diffuse Large B-Cell Lymphoma * Intravascular Large B-Cell Lymphoma * Lymphomatoid Granulomatosis N. Histiocytic, Xanthomatous, Mast Cell, Plasma Cell, and Myeloid Neoplasms * Xanthomata * Xanthogranuloma (Juvenile) * Xanthoma Disseminatum * Verruciform Xanthoma * Rosai-Dorfman Disease * Reticulohistiocytoma * Langerhans Cell Histiocytosis * Cutaneous Mastocytosis * Leukemia Cutis * Plasmacytoma O. Cutaneous Metastases/Implantation * Cutaneous Endometriosis * Cutaneous Metastases Extramammary Paget's Disea