Endoscopic mucosal resection of a bile duct polyp: A case report

BACKGROUND Bile duct polyps are difficult to diagnose and are usually excised by open abdominal surgery or snare polypectomy using choledochoscopy via the T-tube sinus tract. However, these two resection methods require the surgeon to open the abdomen and cut the bile duct to place the "T" tube. Moreover, simple snare polypectomy, without submucosal injection, can only remove pedunculated polyps and not flat polyps. Therefore, a new method is required for the excision of bile duct polyps, including flat polyps.CASE SUMMARY A 63-year-old woman was hospitalized following epigastric pain lasting a month.She had a 30-year history of cholelithiasis and had undergone cholecystectomy because of cholecystolithiasis, and had undergone cholangiolithotomy twice due to choledocholithiasis. Computed tomography （CT） and magnetic resonance imaging showed a communication between the bile duct and duodenal bulb.Inside the communication, CT showed a high-density shadow which was a hypointense lesion in T2 weighted image. The lesion showed no enhancement in T1 weighted image contrast enhanced. Gastroscopy revealed an incarcerated bile duct stone in the anterior wall of the duodenal bulb, which was removed with a basket under gastroscopy. Thereafter, a choledochoduodenal fistula was revealed. Finally, a flat polyp was detected in the lower part of the common bile duct and was removed by endoscopic mucosal resection （EMR） through the fistula. To our knowledge, this is the first reported case of the removal of a bile duct polyp using EMR.CONCLUSION EMR is a safe, effective, and low-cost method for the resection of all bile duct polyps.