[Pigmented cyst of the median raphe of the scrotum in a boy].

To the Editor: Cysts of the median raphe (CMR) are uncommon lesions that result from abnormal embryologic development. In most cases, a urothelial-type or squamous epithelial lining is present, but other rarer histologic variants have been described. One of these, reported infrequently in the literature, is characterized by the presence of melanocytes and melanic pigment in the epithelial lining. A 3-year-old boy was referred to our hospital for surgical removal of a cystic tumor that had been present in the median raphe of the scrotum for 2 years. The lesion was initially a single cyst, but further cysts subsequently appeared along the median raphe of the scrotum. These grew and became progressively pigmented. All cysts were less than 1.5 cm in diameter, soft, painless, and with no signs of inflammation. The lesion was completely excised. On sectioning the surgical specimen, there was a longitudinal canal measuring 0.2 cm in diameter, running the full length of the tissue sample, with several cystic dilatations along its path, the biggest measuring 1.5 cm. The canal and the cysts were filled with a yellow pasty material. Histologically, both the canal and the cystic dilatations showed an epithelial lining in which areas of pseudostratified cylindrical epithelium (Figure 1) alternated with keratinized stratified squamous epithelium (Figure 2). Many areas containing intracytoplasmic melanin were observed in the epithelium, both at the basal level and in upper strata (Figure 3). In addition, some vacuolated melanocytes could be observed in