Cholecystocolic fistula caused by gallbladder carcinoma: preoperatively misdiagnosed as hepatic colon carcinoma.

Cholecystocolic fistula secondary to gallbladder carcinoma is extremely rare and has been reported in very few studies. Most cholecystocolic fistulae are late complications of gallstone disease, but can also develop following carcinoma of the gallbladder when the necrotic tumor penetrates into the adjacent colon. Although no currently available imaging technique has shown great accuracy in recognizing cholecystocolic fistula, abdominopelvic computed tomography may show fistulous communication and anatomical details. Herein we report an unusual case of cholecystocolic fistula caused by gallbladder carcinoma, which was preoperatively misdiagnosed as hepatic flexure colon carcinoma.