Sebaceous gland neoplasia.

Neoplasms with sebaceous differentiation cover a broad spectrum. They range from benign sebaceous hyperplasia and adenomas to locally infiltrative sebaceous epitheliomas which have biologic behaviors similar to basal cell carcinomas, to sebaceous carcinomas which can have very malignant biologic behaviors. In this paper, we have purposely excluded the nevus sebaceus of Jadassohn, a nevoid tumor composed of several cutaneous elements. As sebaceous glands are only one part of this tumor, it is better classified as an organoid nevus.