Newborn with an abdominal mass

US and enema of colonic atresia due to in-utero cecal volvulus
Transverse US of the abdomen (left) shows a large round meconium filled lesion anterior to the right kidney which is at the bottom left of the image. AP image from an enema (right) shows a microcolon with the cecum in the midline of the abdomen. The terminal ileum could not be refluxed.

The diagnosis was a meconium-filled cecum causing in-utero cecal volvulus and subsequent colonic atresia.