Sebaceous differentiation in adenoid cystic carcinoma of the parotid gland.

The first reported case of sebaceous differentiation in adenoid cystic carcinoma is presented. The tumor arose in the superficial lobe of the left parotid gland of a 48-year-old white man, had a predominantly solid histologic pattern, and manifested focal sebaceous differentiation in each of three recurrences over a two-year period. Review of the medical literature suggests that sebaceous differentiation is a normal property of some salivary ducts and may be found in any type of salivary gland neoplasm which has a ductal component. The differential diagnosis of sebaceous and clear cell lesions of salivary glands is discussed.