Background : A cholecystocolonic fistula (CCF) is a rare surgical entity (1 in every 10,000 cholecystectomies), often with an atypical presentation. In this report, a 59-year old male with CCF from a hepatic flexure tumor is presented.

Methods : The patient underwent ERCP with stone extraction which prompted relief of symptoms but eventually noted bowel changes, melena, and loss of appetite. Abdominal CT scan showed a circumferential irregular colonic wall thickening involving the hepatic flexure with luminal narrowing that was intimately related to the thickened gallbladder with poorly-defined planes. No intraluminal stones/fistula were seen. A colonic primary with exophytic growth versus gallbladder neoplasm with local invasion were considered. Colonoscopy showed a 2x2cm nodular mass with mucosal infiltration with an inconclusive biopsy. Tumor markers were normal. Patient eventually underwent an extended right hemicolectomy en bloc radical cholecystectomy.

Results : The specimen showed the gallbladder converted into fibrotic tissues filled with subcentimeter stones and densely attached to the liver and the colon with connection from the colon and the gallbladder. The patient was discharged well and the pathology showed xanthogranulomatous cholecystitis and no malignant cells seen. The colonic segment showed chronic active colitis.

Conclusions : Even with advanced imaging modalities, a definite preoperative diagnosis may still be difficult to arrive at. Since many cases of CCFs are diagnosed only intraoperatively, surgeons must be prepared for a potentially more extensive surgical procedure to properly manage such cases. In the absence of a definite histopathologic diagnosis, an oncologic resection is deemed most appropriate management just as in this case.