Ch. 4 - Pilar & sebaceous neoplasms Flashcards
Pilomatricoma (calcifying epithelioma of Malherbe)
Large ball with internal trabeculae. Basophilic cells keratinizing to form shadow cells. Calcification (or bone fomration!) with giant cell granulomas.
Pilomatrical carcinoma
Rare atypical and infiltrative lesions that arises in long-standing pilomatricomas.
Trichoblastoma
Blue follicular tumors composed of basaloid cells. No retraction artifact. Stroma resembles normal fibrous sheath with contentric collagen and papillary mesenchymal bodies.
Trichoepithelioma
A type of trichoblastoma with finger-like projections and cribriform nodules.
Name 3 syndromes associated with trichoepitheliomas.
Multiple trichoepitheliomas (AD-inherited)
Brooke-Spiegler syndrome (+cylindromas)
Rombo syndrome (+milia, hypotrichosis)
Desmoplastic trichoepithelioma
Firm doughnut-shaped lesion with central dell and Paisley-tie pattern. Red desmoplastic stroma. Affects young women.
Name 5 lesions that show “Paisley-tie” morphology.
Desmoplastic trichoepithelioma
Microcystic adnexal carcinoma
Morpheaform BCC
Eruptive syringomas
Syringomas
Lymphadenoma (adamantinoid trichoblastoma)
Tumor islands with 1-2 layers of basaloid cells peripherally and clear/inflammatory cells centrally.
Fibrofolliculoma
Fibrous pink orb with radiating epithelial strands. No hair fibers.
*associated with Birt-Hogg-Dube syndrome*
Trichofolliculoma
Many small hair follicles emptying into a large follicular infundibulum. Many small hair shafts.
Trichoadenoma
Multiple “red doughnuts” in the dermis resembling follicular infundibulum. Often in pairs?
Basaloid follicular hamartoma
Resembles infundibulocystic BCC (distinguish clinically). Can be multiple (AD-inherited) with blaschkoid distribution.
Dilated pore of Winer
Resembling a dilated follicular infundibulum, with small radiationg epithelial projections.
Pilar sheath acanthoma
Similar to dilated pore of Winer, but with thick acanthotic fingers
Trichlemmoma
Warty-surfaced lobules of clear cells and peripheral palisading. Outlined by thick glassy eosinophilic basement membranous.
*associated with Cowden’s syndrome*
Desmoplastic trichilemmoma
Smooth outline with surrounding glassy basement membrane. Centrally desmoplastic.
Nevus sebaceus of Jadassohn (organoid nevus)
Broad and alopecic lesion that becomes papillomatous and hyperkeratotic after puberty.
Sebaceous hyperplasia
Cluster of mature sebaceous glands around a patulous follicular opening. Nominal basaloid layer at periphery.
Sebaceoma
Single nodule with varying proportions of basaloid cells (sebacoeous epithelioma) and sebocytes (sebaceous adenoma).
*associated with Muir-Torre syndrome*
Sebaceous carcinoma
Atypical and infiltrative lesion with foamy cells with scalloped nuclei and buckshot spread.
Pilomatricoma (low-power)
Pilomatricoma (high-power)
Pilomatrical carcinoma
Trichoblastoma
