Voluminous perinatal pelvic mass: a case of congenital hydrometrocolpos.

Imperforate hymen is the most frequent congenital malformation of the female genital tract; it usually does not show symptoms until puberty. Only rarely, imperforate hymen manifests itself as an abdominal mass detectable in the prenatal period. We describe a rare case of voluminous hydrometrocolpos, antenatally diagnosed and successfully treated immediately after birth.