Steatocystoma simplex, an entity not previously described, to my knowledge, occurred in 16 women and 14 men. Eleven cysts were situated on the face, six on the limbs, and five on the chest. The clinical diagnosis was usually some type of cyst. The lesions contained yellow fluid. Microscopic findings showed a partially collapsed, thin-walled cyst lined by stratified squamous epithelium with a thick, undulating hyaline cuticle and sebaceous glands in or near the wall. When compared with steatocystoma multiplex and dermoid cysts, the differential features of steatocystoma simplex included its solitary nature, occurrence in adulthood, lack of family history, and intracutaneous location. Just as other dominantly inherited syndromes of multiple benign adnexal tumors, such as cylindromas, trichoepitheliomas, and trichilemmomas, have their counterparts in nonheritable solitary tumors, so steatocystoma multiplex has its parallel in steatocystoma simplex.