Cystic malformation of lower female genital tract resulting in hydrops fetalis: a case report.

Genitourinary tract malformations causing hydrops fetalis are rare. The authors report a case of a female delivered at 32 weeks gestational age following a prenatal diagnosis of an abdominopelvic cystic mass with hydrops fetalis. The neonate was persistently hypoxic with unstable cardiovascular status and survived only 7 days. At autopsy, a cystic malformation replaced the vagina and uterus, associated with lower vaginal atresia and anorectal agenesis. The cyst had interfered with the normal process of Müllerian duct fusion, leading to a longitudinal vaginal septum and bifurcation of endocervix, with absent uterus and fallopian tubes. The urinary bladder was compressed by the cyst, resulting in bilateral hydronephrosis. The cyst impeded the inferior vena caval and umbilical venous circulations and impinged upon the thoracic cavity with resultant pulmonary hypoplasia. This malformation, which might be termed "cystic dysplasia" of the vagina, represents an extreme form of hydrometrocolpos that resulted in hydrops fetalis.