Carcinoma of the uterine cervix with squamous and sebaceous differentiation.

Sebaceous neoplasms, including carcinoma, can exceptionally arise in extracutaneous sites. We present the third known case of carcinoma with sebaceous differentiation in the uterine cervix. Histologic and immunohistochemical features suggested a metaplastic process within an otherwise usual squamous cell carcinoma. We speculate that, by analogy with the skin where the epidermis and the 3 types of adnexa have a common embryologic origin from basal cell layer of the superficial ectoderm, it is possible that endocervical reserve cells, in addition to the well-known capacity of squamous differentiation, retain the potential to give rise to appendages including sebaceous glands.