Syringocystadenoma papilliferum

Definition

A rare non-malignant adnexal neoplasm that originates from the apocrine or eccrine sweat glands and is characterized histologically by cystic, papillary, and ductal invaginations into the dermis lined by double-layered outer cuboidal and luminal high columnar epithelium and connected to the epidermis. Dilated capillaries and a dense infiltrate of plasma cells are characteristic. Clinically, lesions are asymptomatic with a heterogeneous, non-distinctive appearance ranging from skin-colored to pink papules or plaques, occurring most commonly in the head and neck area.