Derm Path Flashcards
Keratoacanthoma, mimicing?
Pagetoid SCC mimickers?
Fibroepithelial pinkus
Well diff glassy proliferation of atypical keratinocytes in crateroform pattern; microabscesses associated with
Mimics: Chromoblastomicosis (copper pennies)
SCC: Pagets and Melanoma (look for bridges)
FP: BCC growing down adnexal structure; mimics (syringofibroadenoma and poroma)
Trichilemma?
Finding at edges?
Small solitary asymptomatic papular lesion on face
Shart circumscribed borders, lobules into upper germis with continuitiy with epidermis
Peripheral layer of clear/glycogenated palisading cells with thicken glassy basement membrane!!!
Tumor of follicular infundibulum?
Trichofolliculoma?
Subepidermal tumor composed of reticulated cords and nests of pale/pink staining glycogen containing cells (not blue which seperates from superficial basal)
Trichofolliculoma: One or several dialted hair follicals and radiates small hair follicles (little babies)
Trichoepithelioma (mimics BCC)
Islands of basaloid cells with some peripheral palisading
Fibroblastic stroma; Epithelial structures resembling hair papillae and aggregation of fibroblasts around these (papillary mesenchymal bodies)
Desmoplastic Trichoepithelioma?
Face; well circumscribed in upper and mid dermis; central depression
Cords and small nests of basaloid cells with scant cytoplasm
Many keratinous (horn cysts)
How to DDx Demsmoplastic trichoepithelioma vs BCC?
Trichoepitheleoioma associations?
DTE: Lacks retraction and apoptosis (more common BCC)
DTE: SPindle cells around islands (CD34+) vs CD34- cells in BCC
BCC: Diffuse BCL2 vs DTE in basal layer only
Multiple family: CYLD gene on 16q12-13; Brooke-Spiegler syndrome
Cowden’s Multiple trichelemmomas (PTEN 10q23.31)–PTEN hammartomous tumor
Pilomatricoma?
Differentations to hair matrix and hair cortex of inner sheath
Calcifying epithelelioma of Malherbe
Sharp demarcation in lower dermis/subq
Basophilic cells and SHADOW CELLS
Often calcified
Fibrofolliculoma/trichodiscoma?
Fibrofolliculoma: Cords/strands of epithelial cells, 2-4 cells thick radiating from follicular structrure with a surrounding well circumscribed proliferation of loose connective tissue with fine fibers
Looks a bit like neurofibroma/desmoplastic melanoma but key is “radiating strands” in epidermis
Trichodiscoma: Well demarcaded but non encapsulated; come collarette of follicularsebaceous cells but no surface bridging
Birt-Hogg-Dube gene, transmission pattern?
Associated wtih?
AD, FLCN (BHD) Ch 17p12 folliculin protein
Oncocytic neoplasms and chromophobe RCC, Cutaeneous fibrofolliculomas, Lung susts and spontaneous pneumothorax
Merkel cell?
Cutaneous NE carcinoma
CK20+ dot like, P63+ (bad prognosis), Synapto and Chromo +
Does not palisade like BCC
Molluscum casued by?
Verruca vs Condyloma Accuminata
Pox virus with Henderson Patterson Bodies
Condyloma: more mamillated with more vessels; also more likely to be in genetals
Cylindroma?
Spiradenoma?
Dermal tumor of “irregular hsapped” island/chords in JIGSAW PUZZLE with HYALINE MEMBRANE AROUND
Spiradenoma: Basophilic nodules in dermic; trabecular arrangement of small dark cells and larger paler cells with prominent stroma (similar to Cylindroma and can sign out together)
Syringoma?
Clinical: Multiple small papules on lower eyelids and cheeks (critical to differentiate from microcystic adnexal carcinoma)
Dermal tumor of small ducts; 2 layers of epithelium, comma tails, strans of basaloid epithelium, dense REDISH stroma
Microcystic adnexal carcinoma?
Dilated ducts and keratin filled cysts in upper dermis, PNI is present if deep biopsy
These lesions extend deep to diff from synringoma
Clinical: Plaque (one) on lips normally upper
Eccrine Poroma?
Basaloid proliferation; epidermal connection; has DUCTS
Looks like SebK but “funny”