Prenatal diagnosis of a bronchogenic cyst in an unusual site

We report a rare case of a subdiaphragmatic cyst, diagnosed prenatally duri ng routine ultrasound screening at 25 weeks' gestation. Serial ultrasonogra phic evaluation demonstrated a slight increase in the size of the cyst duri ng pregnancy. On the basis of the anatomic site and the sonographic feature s of the lesion, four diagnostic hypotheses were postulated: cystic neurobl astoma, adrenal hemorrhage, duplication of the inferior third of the esopha gus and retroperitoneal cystic lymphangioma. A healthy baby, weighting 3300 g and with Apgar scores of 8 and 9, was deli vered vaginally at term. He underwent successful surgery at the age of 3 mo nths. Thee operative course was uneventful and the baby is currently doing well. Histology revealed a bronchogenic cyst.