Antenatal diagnosis of hydrometrocolpos with Mullerian duplication on ultrasound and fetal MRI: case report and literature review

Fetal abdomino-pelvic cystic lesions are uncommon and can have varied etio-pathogenesis. Most commonly they originate from the gastrointestinal or genitourinary tract. These include choledochal cyst, hydronephrosis, renal cyst, mesenteric/omental cyst, ovarian cyst, meconium pseudocyst, and hydrocolpos/hydrometrocolpos among others. Fetal hydrometrocolpos is rare with a reported incidence of 0.006% and its diagnosis requires a high index of suspicion. Antenatal ultrasound and magnetic resonance imaging (MRI) is invaluable in diagnostic evaluation. This case report describes the imaging features of antenatally detected congenital hydrometrocolpos with Mullerian duplication secondary to cloacal malformation using antenatal ultrasound and MRI. Per-operative findings and other possible differential diagnoses are discussed along with a brief review of literature.