Membranous basal cell adenoma of the hypopharynx.

A membranous basal cell adenoma arose from the minor salivary glands in the hypopharynx of a 62-year-old man. Features distinguishing the membranous variant from other forms of basal cell adenoma include the following: (1) abundant reduplicated basement membrane material, (2) the presence of sialomucin-containing cells, and (3) the lack of distinct encapsulation. To our knowledge, this is the first report of a basal cell adenoma of the hypopharynx, and the first report of the membranous variant in a minor salivary gland.