Sebaceous carcinoma associated with Bowen's disease: a case report with emphasis on the pathogenesis of sebaceous carcinoma.

Extraocular sebaceous carcinoma is a relatively rare skin appendage carcinoma [1]. Although ocular sebaceous carcinoma is thought to arise from the Meibomian glands and glands of Zeis, there is no evidence that extraocular sebaceous carcinoma arises from pre-existing sebaceous glands [2]. Most sebaceous carcinomas are invasive [1], however, only a few cases of sebaceous carcinoma associated with intraepidermal squamous neoplasia (actinic keratosis or Bowen’s disease) have been reported [3-8]. These cases suggest that extraocular sebaceous carcinoma can originate from pre-existing intraepidermal squamous neoplasia [8]. Herein, we report an additional case of sebaceous carcinoma associated with Bowen’s disease and discuss the pathogenesis of sebaceous carcinoma.