Retroperitoneal alimentary tract duplications detected in utero.

The prenatal diagnosis of numerous congenital anomalies has become routine. The prenatal diagnosis of cystic lesions of the retroperitoneum can be due to a variety of renal, gastrointestinal, or adrenal lesions. This finding demands aggressive postnatal follow-up to rule out the possibility of cystic adrenal neuroblastoma. We report the first cases of retroperitoneal cystic masses diagnosed in utero that ultimately proved to be enteric duplications. Therefore, the differential diagnosis of cystic masses of the retroperitoneum found prenatally should be expanded to include enteric duplication cysts.