Panfolliculoma
Cystic areas resembling infundibulum with stratified squamous epithelium, granular layer, and basket-weave stratum corneum Areas resembling internal and external root sheath Foci of matrical epithelium Areas resembling hair bulb with…
Angiomyofibroblastoma
Cells characteristically cluster around thin-walled capillaries • In postmenopausal patients, cells are more spindled, and overall cellularity is low • Mature adipose tissue component in minority of cases • Some cases show morphologic…
Cellular Neurothekeoma
Subset have brisk mitotic activity (> 5/10 HPF in 20%; > 10/10 HPF in 5%) Atypical mitotic figures may be seen Ancillary Tests • Often positive for variety of nonspecific markers,…
Proliferating Pilar (Tricholemmal) Cyst/Tumor
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…
Papillary Endothelial Hyperplasia (Masson Tumor)
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…
Lymphangioma and Superficial Lymphangioma
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…
Cutaneous Mixed Tumor (Chondroid Syringoma)
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…
Apocrine Tubular Adenoma
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…
Microcystic Adnexal Carcinoma
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…
