Uncategorized

  • Digital papillary adenocarcinoma (aggressive digital papillary adenocarcinoma)

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    Rare sweat gland carcinoma which may be confused with a papillary metastasis and should be differentiated from papillary eccrine adenoma. Recently has been shown to be associated with HPV42 in the majority of cases Leiendecker et al 2023). A small subset is associated with mutations in BRAF V600E. Clinical features •Very rare, often aggressive •Volar fingers,…

  • Nevus sebaceus (sebaceous nevus of Jadassohn, organoid nevus)

    Clinical features •Fairly common lesion present at birth or becomes obvious in the 1st 2 decades (0.3% of newborns) •M=F •No racial predilection •Solitary yellow, waxy, circumscribed lesion up to 6.0 cm in diameter most often on the scalp or face although it can arise just about anywhere •It characteristically enlarges & becomes warty during puberty & adulthood…

  • Dilated pore of Winer

    Clinical features •Common, generally solitary, asymptomatic, keratin plugged, comedone-like cystic invagination •Few mm to 1 cm or more •Face & neck •Exceptionally on trunk •2M:1F •Generally, middle-aged or elderly Histological findings •A keratin-plugged, dilated  follicular infundibulum lined by squamous epithelium and showing epithelial strands and/or buds emanating from ”cyst” wall •The epithelium is often acanthotic showing hyperkeratosis & parakeratosis •Exceptionally, vellus hair &/or sebaceous glands (overlapping…

  • Hidradenoma papilliferum

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    This tumor occurs exclusively in females and is thought to represent an external genital equivalent to breast intraduct papilloma. It is probably derived from the ano-genital mammary-like glands Clinical features •Almost all cases have arisen in females, generally white & young-middle-aged •Occasionally symptomatic- pruritus, pain etc •Male cases represent misdiagnosed cystic apocrine hidradenoma •Small, asymptomatic solid/cystic papule…

  • Syringocystadenoma papilliferum (SCAP) & syringocystadenocarcinoma papilliferum

    Clinical features •Generally, presents in childhood as a solitary gray/brown warty lesion on the scalp with a moist surface •Can arise at other sies including face, neck, trunk & legs and elsewhere •Can be present at birth •A common tumor in a background of nevus sebaceus •Rarely linear lesion •Segmental following lines of Blaschko •May arise in association with benign apocrine cysts & sweat…

  • Papillary eccrine adenoma

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    Clinical features •Very rare benign tumor that shows a predilection for the distal extremities •4F:1M •Black> White races •Slowly growing, asymptomatic, flesh colored or pink nodule (0.5-4 cm diameter) Histological features •Circumscribed nodule composed of ducts & cysts embedded in a dense fibrous stroma sometimes associated with lymphoid aggregates/germinal centers •Ducts lined by double-layered epithelium- small inner, uniform cells with eosinophilic…

  • Pilomatricoma (pilomatrixoma, calcifying epithelioma of Malherbe)

    Clinical features •Slowly growing, 0.5-3 cm hard nodule •Cheek is the commonest site but may also present elsewhere on the head, neck, trunk & limbs •Two age peaks- childhood and the elderly •Sometimes tender •Giant variant •Familial multiple tumors (autosomal dominant) •Rare syndromic associations (autosomal dominant- Gardner-, Turner-,  & Rubinstein-Taybi syndromes & myotonic dystrophy Histological features •CTNNB1 gene mutations •Differentiates towards follicular matrix •Multilobulated tumor in dermis +/- subcutaneous fat with a fibrous pseudocapsule •Basophilic small…

  • Syringoma

    Clinical features •Commonly present on the lower eyelids & upper cheeks as multiple flesh colored or yellow/brown small (1-3 mm) papules; although they can present just about anywhere •Vulval syringomas are often associated with marked pruritus •F>>M •Teenagers & young adults •May be familial, autosomal dominant (16q22) •Increased incidence in Asian females •Unilateral linear nevoid following Blaschko’s lines •Plaque variant (may mimic microcystic adnexal carcinoma) •Associations with Down’s-,…

  • Cylindroma

    Clinical features •Sporadic or familial •MYB-NFIB fusion gene in many sporadic tumors  •CYLD gene mutation in Brooke-Spiegler syndrome & some sporadic tumors •Predilection for head, neck & particularly scalp although may present elsewhere •Multiple scalp tumors-turban tumor •Linear variant •9F:1M •Familial cases •Brooke-Spiegler syndrome Histological features •Dermal based •Jigsaw/mosaic pattern arrangement of variably sized lobules of tumor cells with surrounding think, eosinophilic hyaline basement membrane •Intralobular hyaline basement membrane material droplets •Outer…

  • Spiradenoma

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    Clinical features •Tender or painful, sharply delineated typically blue 1-3 cm dermal nodule nodule •Ventral skin, most on the upper half of the integument (head, neck & trunk) •Rarely multiple lesions 2nd-4th decade •Giant variant •Linear, Blaschkoid, variants •Autosomal dominant familial variant •May occur as part of the Brooke-Spiegler syndrome Histological features •Nodule/multiple blue encapsulated nodules in the…