Unusual Presentation of Colonic Carcinoma as a Psoas Abscess

A psoas abscess, also known as an iliopsoas abscess (IPA), is a collection of pus in the iliopsoas muscle compartment of the pelvis. It can present with vague clinical symptoms, which results in a delay in its diagnosis. The aetiology depends on demographic areas, but the most common cause is tuberculosis in the developing countries. IPA rarely occurs due to colonic cancer in the developing countries. Here are two case reports of middle-aged, immunocompetent males who had symptoms of pain in right flank and right iliac fossa associated with fever. CT scans of the abdomen and pelvis confirmed the clinical suspicion of IPA. The abscesses were drained surgically; peri-operatively, gelatinous material along with granulation tissue was noted. The histopathology indicated mucinous adenocarcinoma. Therefore, all patients who present with a psoas abscess should have a complete evaluation.