Pathology Flashcards
Cowdry Type A Bodies
intranuclear eosinophilic amorphous bodies surrounded by a clear halo
- seen in VZV/HSV
Asteroid Bodies
- intracellular stellate eosinophillic inclusion bodies withing a multinucleated giant cell (sarcoidosis, foreign body rxn)
- extracellular central spore surrounded by radiating homogeneous eosinophilic material (sporotrichosis –> splendore-hoeppli phenomenon)
Caterpillar Bodies
wavy eosinophilic material in the basal epidermal layer or roof of a blister
- seen in PCT and EEP
Donavan Bodies
intracytoplasmic bacteria in infected histiocytes
- seen in granuloma inguinale
Dutcher Bodies
eosinophilic intranuclear inclusions of Ig in malignant plasma cells
- seen in multiple myeloma
Henderson-Patterson Bodies
large eosinophilic inclusion of viral protein in keritinocytes
-seen in molluscum contagiosum
5 cells that stain positive with S100
melanocytes langerhans cells schwann cells (nerve in general) eccrine cells adipocytes
Mucin stains
colloidal iron, toluene blue, alcian blue
What is Factor XIIIa positive?
Dermatofibroma, angiofibroma, fibrous papule of nose, acquired digital fibrokeratoma, malignant fibrous histiocytoma, xanthogranuloma
What is CD34 positive?
Dermatofibrosarcoma protuberans, pleomorphic fibromas, sclerotic fibroma, spindle cell lipoma, nephrogenic fibrosing dermopathy
What do you call a tumor made of cuboidal cells with ample pink cytoplasm and cuticle-lined ducts that connects to the epidermis? What if it is confined to the epidermis? The dermis? If not connected to epidermis?
Poroma; if in epidermis only - Hidroacanthoma simplex (ddx clonal SK but has ducts); if in dermis - Dermal duct tumor; if not connected to epidermis - Nodular Hidradenoma (dermal nodule)
Staining pattern for Xanthogranuloma
CD68 +, Factor XIIIa +, vimentin +; CD34 -, S100 -, CD1a - (Bonus: if multiple xanthogranulomas, check eyes…increased risk glaucoma or anterior-chamber hemorrhage)
Where can you see Touton Giant Cells?
Dermatofibroma (can contain hemosiderin = ringed lipidized siderophages), juvenile xanthogranuloma, necrobiotic xanthogranuloma
Differential for neutrohils in the stratum corneum?
Psoriasis, Tinea, Impetigo, Candida, Seborrheic Dermatitis, Syphilis (“PTICSS”)
Differential for painful tumors…
Blue rubber bleb, Leiomyoma, Eccrine spiradenoma, Neuroma, Dermatofibroma, Angiolipoma, Neurilemmoma, Endometrioma, Glomus tumor, Granular cell tumor (BLEND AN EGG)
Paisley tie pattern Ddx:
Desmoplastic trichoepithelioma, morpheaform BCC, MAC, syringomas
What is seen on staining of minocycline hyperpigmentation?
Perls –> hemosiderin (iron) BLUE within macrophages; Fontana Masson –> melanin BLACK
What is the histopath Ddx of blue tumors?
“LEMONS” = lymphoma, Ewing’s sarcoma, Merkel cell carcinoma + Melanoma, Oat cell carcinoma of lung, Small cell endocrine carcinoma
Ddx of flame figures? What are flame figures made of?
Eosinophilic cellulitis (Wells syndrome), arthropod bites and stings (tick, bee, flea, spider), mastocytomas, scabies, prurigo nodularis, eczema, dermatophyte infections
Made of necrobiotic collagen and major basic protein (from eos)
Where do mast cells live and what stains them?
Greatest density in papilary dermis; Giemsa stains granules purple; Leder stains granules red.
What is the differential diagnosis of a Grenz zone?
Granuloma faciale, lepromatous leprosy, leukemia cutis, B-cell lymphomas
What is the differential diagnosis of striking upper dermal edema?
“PUBES” = PMLE (lymphs superficial and deep), Pernio, Urticaria, Bug bite, EM (superficial lymphs), Sweets (neuts)
What is the normal skin ddx on histopathology?
Tinea, Ichthyosis, Porokeratosis, Inferface dermatitis (GVHD and DM can be subtle), Vitiligo, Alopecia, Myxedema, Scleromyxedema, Connective tissue abnormalities (nevi, anetoderma), Argyria, Urticaria, TMEP
What is the Ddx of a square punch biopsy?
Pretybial myxedema, morphea, scleroderma, scleredema, NLD
