A Case of Steatocystoma Simplex Involving the Scalp.

Steatocystoma is a benign adnexal tumor originating from the pilosebaceous duct junction which can be classified into two groups (steatocystoma simplex and steatocystoma multiplex). Steatocystoma simplex, which presents as a solitary lesion, is very rare. Steatocystoma simplex occurs most commonly on the face and the case reported herein involving the scalp is extremely rare. A 49-year-old man presented for evaluation and treatment of a solitary papule on the right parietal scalp which had persisted for a period of 1 year. The histopathologic examination revealed a thin-walled cyst consisting of stratified squamous epithelium with hyaline cuticle that lacked a stratum granulosum. Based on clinical and histologic findings, we diagnosed this case as steatocystoma simplex of the scalp and report this rare case.