ABSTRACT
Trichoepitheliomas are benign tumors derived from the hair follicle. Some regard it as a distinct variant of trichoblastoma. Trichoblastoma is a benign tumor with mostly follicular germinative differentiation. Tumor of the follicular infundibulum is an uncommon benign adnexal neoplasm. It is a nonspecific lesion seen in middle-aged or older individuals, and often occurs on the face or scalp. The characteristic histopathological feature is a subepidermal plate-like proliferation. Sebaceous adenoma is a benign cutaneous neoplasm of the adnexa with sebaceous differentiation. A spectrum of morphologic features and varying degrees of differentiation can occur within one neoplasm. Microcystic adnexal carcinoma is a rare cutaneous malignant tumor that is locally invasive and often presents with perineural invasion. Sebaceomas are distinctive benign neoplasms of adnexal epithelium histologically differentiating toward sebaceous cells. Clinically, these tumors present as yellow to orange papules or nodules on the face or scalp of older individuals and can be associated with the Muir-Torre syndrome.
