Pigmented median raphe cyst of the penis

摘要

Median raphe cyst represents a relatively rare cystic lesion on the median raphe, which extends from the urethral meatus to the anus. Since the first report by Mermet in 1895,1 several terminologies, including median raphe cyst, 'mucoid cyst of penile skin' and 'genitoperineal cyst of the medium raphe' have been used. There is a general agreement that median raphe cyst is derived from the urethral mucosa or urethral gland (Littre's gland).3 It appears commonly in children or adolescents with a mean size of less than 20 mm.4 Rarely, median raphe cyst contains melanin and melanocytes and clinically has a pigmented appearance. Such a cyst is called pigmented median raphe cyst.