Parameatal cyst. EM analysis of pathogenesis

A case of parameatal cyst of the glans penis is reported. Two years ago, a 20-year-old man first noticed a 4 mm blue-black tumor on his left side of the external urethral meatus. The size of tumor increased, so he visited our clinic. There was no history of trauma to or infection of the genitalia. This tumor was totally excised and examined histologically with a light and an electron microscope. Histological examination of the cyst wall revealed a monolayer of a tall columnar epithelial lining with inflammatory change. In the sublayer of the wall, areolar connective tissue was found. An electron microscopic photograph showed microvilli in the cell, the basement membrane, and in secretion granules. It thus was considered that the cyst origin was related with the embryonal development of the parameatal ducts, and that the cyst arose from the occlusion of the ducts.