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…

 Sometimes with true glandular formation • Round vesicular nuclei with prominent nucleoli • Abundant clear cytoplasm  May contain intracytoplasmic melanin • Absence of intercellular bridges • Paget cells often extend to adnexal structures • Flattened…

 Haphazard arrangement  Thin fascicles rather than solid growth pattern  No atypia  No mitoses  No necrosis  Immunohistochemistry (+) for muscle markers Top Differential Diagnoses • Cutaneous leiomyoma (pilar leiomyoma)  Occurs in adults…

 Also associated with organ transplantation, systemic steroids, and leukemia Clinical Issues • Occurs in both adults and children • Can involve any cutaneous site; uncommonly involves mucosal sites, deep soft tissues • Typically…

 Located centrally within lobules • Basaloid/germinative cells at periphery of lobules • Cytologic atypia not prominent • Presence of mitotic figure in germinative layer does not indicate malignant potential Ancillary Tests • Sebocytes express…