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.