Urethroid cyst.

Cysts found on the ventral surface of the penis have been pathogenetically ascribed to defective embryologic closure of the median raphe, to anomalous developmental rests of the periurethral glands of Littre, and to the ectopic development of apocrine cystadenoma in the penile skin. This case reports a previously unrecognized but compelling pathogenesis for at least some ventral penile cysts, namely the anomalous congenital outgrowth of the entodermal urethral lining, giving rise to what is here designated as a urethroid cyst.