Incidental removal of distal common bile duct adenoma after plastic stent placement.

We report a case of a 53-year-old man who presented with a history of recurrent fever with intermittent jaundice over a few months. Ascending cholangitis was suspected. Abdominal ultrasound showed no gallstone and an only slightly dilated common bile duct (CBD). The patient’s blood tests were normal. The patient was referred for endoscopic ultrasound (EUS). In the endoscopic suite, the patient underwent deep sedation with full anesthetic monitoring. EUS was performed using a curvilinear echoendoscope (GF UC 140P; Olympus, Tokyo, Japan). The EUS findings showed an isoechoic oval shaped mass of 1.1×0.7cm at the distal CBD, without CBD dilation (●" Fig.1). The patient then underwent endoscopic retrograde cholangiopancreatography (ERCP) using the duodenoscope (Olympus TJF-160, Olympus America, Center Valley, Pennsylvania, USA). The ampulla seemed normal on duodenoscopy (●" Fig.2). A cholangiogram revealed a 12-mm CBD with an irregular shaped filling defect, size 11×20mm, at the distal CBD (●" Fig.3). After endoscopic sphincterotomy, a polypoid mass of 1.5×1.0cm popped out (●" Fig.4). The stalk of this polyp was inside the CBD. We decided to take a biopsy from the polyp, and planned for polypectomy later, so a 10-Fr plastic stent (Cotton-Leung biliary endoprosthesis, Wilson-Cook Medical Inc., Winston-Salem, North Carolina, USA) was inserted for biliary drainage (●" Fig.5). Pathological analysis showed a tubular adenoma with low grade dysplasia. The patient was scheduled for polypectomy 2 weeks later. During the second procedure, the polyp had disappeared, thus endoscopic retrograde cholangiography was performed. The cholangiogram showed no residual filling defect at the distal CBD. Overtube-assisted cholangioscopy using an ultraslim gastroscope showed only a residual small ulcer of about 4mm diameter at the distal CBD (●" Fig.6). Our hypothesis for this unexpected event was that the pressure from the plastic stent resulted in stalk necrosis. To our knowledge [1–3], such a case has not been previously reported.