Benign Parapapillary Choledochoduodenal Fistula Associated with Ampullary Carcinoma: Case Report and Literature Review

Parapapillary and periampullary choledochoduodenal fistulas (CDF) are rare conditions. We here report a case of benign parapapillary choledochoduodenal fistula associated with early ampullary carcinoma (pT1NoMo). A 54-year-old Jordanian man had recurrent cholangitis without clinical jaundice. He had marked elevation of the alkaline phosphatase (AP) and Gamma Glutamyl Transferase (GTT). Abdominal ultrasonography showed distension of the gallbladder with dilatation of the common bile duct (CBD). Duodenoscopy showed a swollen ampulla with no intraduodenal growth. Cannulation the orifice of the papilla of Vater failed. But endoscopic biopsy revealed adenocarcinoma. Magnetic resonance cholangiopancreatiocography showed a dilated bile duct with a filling defect in its most distal part. With the diagnosis of ampullary carcinoma, the patient underwent pylorus-preserving pancreatico-duodenectomy (PPPD). The gross and microscopic examination of the resected specimen showed a dilated CBD, a small-sized benign choledocho-duodenal fistula to the CBD above the tumor, and a non-dilated pancreatic duct that opened above the tumor. The small-sized fistula was missed by all used diagnostic procedures. This communication presents a unique case of association between ampullary carcinoma with benign small sized parapapillary CDF that caused cholangitis with marked elevation of AP and GTT but without clinical jaundice. The benign CDF may cause cholangitis and together with the high bilio-pancreatic junction may increase the risk of biliary cancer.