Psoas abscess resulting from perforating carcinoma of the sigmoid colon. Report of a case.

We report a case of a left psoas abscess resulting from a perforating carcinoma of the sigmoid colon. The chief complaints were edema of the left leg and pain in the left thigh. Single and double contrast barium-enema film demonstrated an extrinsic inflammatory mass distorting the sigmoid colon. A preoperative diagnosis of sigmoid carcinoma was not made on these examinations, nor on flexible colonoscopy. Carcinoma of the colon should be considered as a cause of an unexplained psoas abscess.