Multicystic squamous neoplasm composed of mature keratinocytes lining keratin-filled spaces Etiology/Pathogenesis • Postulated that most cases arise in preexisting pilar (tricholemmal) cyst; may be related to chronic inflammation or trauma Clinical…
PEH lacks nuclear atypia, tumor cell necrosis, and mitotic activity present in angiosarcoma • Hemangioma • PEH-like changes may occur in hemangiomas complicated by thrombosis • Arteriovenous malformation (AVM) PEH-like changes may occur…
Large, Deep LymphangiomaClinical photograph shows a large, deep lymphangioma (cystic hygroma) on the lateral neck of a child. Superficial LymphangiomaThis example of a superficial lymphangioma shows widely dilated spaces in…
Chondroid Syringoma/Cutaneous Mixed Tumor Low MagnificationLow magnification shows a well-circumscribed tumor composed of epithelial islands with easily identifiable glandular/ductal structures embedded in a myxoid and hyaline stroma. Cutaneous Mixed Tumor…
Tumors in anogenital area may truly represent adenoma of anogenital mammary-like glands Tumors in eyelid should be distinguished from endocrine mucin-producing sweat gland carcinoma • F > M (2:1) • Adult patients…
MAC on CheekClinical photograph of microcystic adnexal carcinoma (MAC) on the cheek of a middle-aged woman shows a flesh-colored papular to plaque-like lesion. MAC at Low MagnificationScanning magnification of a…
Most cases occur in adults but some occur in children May show significant overlap with Dabska tumor, with prominent papillary structures • Composite hemangioendothelioma Composed of at least 2 distinct HE…
High risk of renal cell carcinoma Also, pulmonary cysts and pneumothoraces Clinical Issues • Typically present as multiple small papule(s) on face Microscopic • FF shows proliferation of thin, anastomosing epithelial cords…
Histologically and genetically identical to conventional deep LGFMS Clinical Issues • Appear to represent 10-20% of reported cases of LGFMS • Often adults (typically 3rd-4th decade), but wide range Up to 1/3…
Solitary, dome-shaped, flesh-colored papules on nose or central face • Adenoma sebaceum: Angiofibromas associated with tuberous sclerosis Grouped papules or nodules with butterfly distribution on central face • May clinically mimic basal…
