Lipomatous nevus and urethral caruncle mistaken for ambiguous genitalia in a female infant.

We report the case of a 46,XX infant referred at 3 months of age for evaluation of ambiguous genitalia with no palpable gonads. The phallus was replaced by a homogeneous peduncular structure covered by skin, and a second peduncular structure covered by mucosa was located between the labia minora above the urethral meatus and the vaginal opening. There were no associated anomalies, and she had normal growth and neuromotor development. During surgery to remove these structures, a bifid clitoris was detected and cystoscopy and vaginoscopy revealed normal female urethra and vagina. The structure located on the phallic region was a superficial lipomatous nevus, and the other mass was a congenital urethral caruncle with ectopic migration/differentiation of colonic epithelium into ventral and anterior part of the urogenital sinus. Both genital lipomas and congenital caruncles of the female urethra are very rare and their etiology is unknown. There is no previous report of coincidence of these two rare findings in an otherwise healthy girl.