Excavated mass and double tracking in the sigmoid colon due to colocolic fistula complicating diverticulitis.

Abstract

Intramural abscesses/fistula complicating diverticulitis are uncommon (1, 2) and predominantly described in the sigmoid colon (3). On conventional radiology their appearance is described as having a double tract pattern (4).In a case of fistulous intramural abscess of the sigmoid colon, we report the CT and conventional radiographic features in correlation with histopathologic findings. Case reportA 72-year-old man with a history of prostatic adenocarcinoma classified as Gleason 8 presented a pelvic mass, different from prostate, on physical examination which justified further investigation. He complained of vague abdominal pain and a weight loss of 10 kg for the last 6 months. Several antibiotic therapies for various indications especially urinary symptoms were reported. No fever, no intestinal bleeding was reported.No significant change of the biological inflammatory parameters was found.Computer tomography (CT) of the abdomen showed narrowing of the sigmoid colon and an elongated paracolic soft-tissue mass (6.5 x 3 cm) containing gas and necrotic material as well as dense opacities. No adenopathy were found in the surrounding areas. A colonic excavated mass was suggested, the differential diagnosis including a perforated either primary or metastatic colonic neoplasm, but an invading vesical carcinoma was not excluded (Fig. 1). ple diverticula. It also demonstrated in this narrowed part crossing ridges, tethering of the inferior border and a normal mucosal appearance. A double track pattern was evenly showed, the second track being located along the inferior surface of the involved sigmoid with a indented superior and a regular inferior border. This 6 cm long sinus tract communicated with the true sigmoid lumen (Fig. 2). The Double contrast barium enema (DCBE), undertaken five days after, confirmed the narrowing of midsigmoid and the occurrence of multi-JBR-BTR, 2012, 95: 325-328. We report on a patient admitted for work up of prostatic carcinoma in which CT study showed an excavated mass involving the sigmoid colon and the bladder dome. Barium enema showed a double track pattern associated with diverticular disease. By surgery the mass was separated from the urinary bladder and the sigmoid resected. On pathological exam diverticulitis was evident as well as an organised colocolic fistula in the thickened fibrotic subserosal fat. The usefulness of opacifying the colon is highlighted. EXCAVATED MASS AND DOUBLE TRACKING IN THE SIGMOID COLON DUE TO COLOCOLIC FISTULA COMPLICATING DIVERTICULITIS