Epidermoid cyst of the penis with extension into the pelvis.

A 3%-year-old boy presented with a midline 1.5 X 1.5 X 1 cm. cystic swelling on the ventral apsect of the middle third of the penis 2 years in duration. There was no history of urinary tract infection, hematuria, dysuria, trauma, difficult voiding or variation in the size of the swelling in relation to micturition. The urinary stream was normal. The skin overlying the swelling was normal and free of cyst. The cyst had restricted mobility transversely and there was no movement longitudinally. The swelling was compressible and could be emptied completely but it filled back slowly within 1 minute. A voiding cystourethrogram did not show any urethral or bladder abnormality. During surgery a urethral catheter was inserted. A midline longitudinal incision was made over the swelling. The cyst extended proximally in close proximity to the urethra as a tubular structure. Another midline incision was made in the perineum behind the scrotum to facilitate complete dissection. The cyst was patent until about half a centimeter beyond the urogenital diaphragm, beyond which it tapered into a fibrous tract for about 1 cm. deep into the pelvis. The excised lesion was 7 cm. long and had a teardrop shape with a bulbous distal end (see figure). The sebaceous content of the distal end could be completely emptied into the more proximal tubular portion which otherwise remained empty. The cyst was lined by squamous epithelium and keratin. It did not contain either skin appendage or germ cell layers.