Meconium hydrocele in a female newborn: an unusual cause of a labial mass.

Meconium peritonitis results from in utero perforation of the bowel and subsequent spillage of meconium into the peritoneal cavity. Free communication of the peritoneal space with the processus vaginalis during gestation permits formation of a meconium hydrocele. Meconium hydrocele has been reported in the newborn scrotum but to our knowledge there has been no previous report of meconium hydrocele in the labium of a female neonate. The predominance of meconium hydrocele in the male infant may be due to the obliteration of the processus vaginalis occurring later in the male than in the female fetus.