RESUMEN
The authors report a case of segmental jejunal dilatation that was discovered antenatally and manifested clinically as lower obstruction in a newborn boy. The antenatal ultrasound findings at 29, 30, and 31 weeks' gestation showed a constant hypoechogenic image (6 x 3 cm in diameter) localized to the right flank of the fetal abdomen, thought to be situated in the right colon. A prenatal diagnosis of incomplete right colonic stenosis was considered. In the immediate postnatal period, there were clinical manifestations of intestinal obstruction; however, results of a contrast enema and rectal biopsies were normal. An upper gastrointestinal contrast study showed a dilated jejunal loop situated approximately 15 cm from the ligament of Treitz. During surgery, a large dilated jejunal loop (7 cm in diameter, 15 cm in length) was found and resected. Histopathologic examination confirmed the diagnosis of segmental jejunal dilatation. This is the first antenatal illustration of this rare pathology, and it supports the hypothesis of a congenital origin for this anomaly.