Retrogastric colon: CT demonstration of anatomic variations.

In a series of 9,400 body computed tomographic (CT) scans of adult patients, a retrogastric course of the transverse colon with interposition of colon between the pancreatic body-tail and stomach was identified in 18 patients (0.2%). Three other patients (0.03%) had retrosplenic, retrogastric colon with transverse colon interposed between the spleen and posterior diaphragm. Three of the 18 patients with pancreaticogastric interposition also had small bowel malrotation. Clinically, no symptoms attributable to retrogastric colon were found. Retrogastric colons probably result from mild embryologic abnormalities of bowel rotation and fixation. Radiologically, colon in the area of the lesser sac must be differentiated from the normal duodenojejunal flexure, a perforated viscus, and abscess.