Unexpected minor duodenal papilla during endoscopic submucosal dissection

A 77-year-old man was diagnosed with a flat-elevated tumor on the medial wall of the oral side of the major duodenal papilla (Fig. 1a, b). Considering the tumor location, the pancreas was inspected for divisum before the endoscopic submucosal dissection (ESD) was performed; none was evident. During the ESD, a small elevation suspected to be a minor duodenal papilla was observed on the oral side of the lesion. Since the lesion was located above the minor papilla, an en bloc resection was performed by careful dissection of the minor papilla with a Clutch Cutter 3.5 mm (Fujifilm, Tokyo, Japan). To prevent delayed adverse events due to postoperative exposure to bile and pancreatic juice, the mucosal defect was closed with avoidance of the minor papilla (Fig. 1c). Although there was no pancreas divisum, prophylactic treatment included aggressive hydration and antibiotics in order to prevent severe pancreatitis from the resection of the lesion on the minor papilla. The patient developed pancreatitis on postoperative day 1, but the symptoms were not severe due to the preemptive measures taken. The patient was discharged safely on postoperative day 14 (Fig. 1d). The pathological examination involved endoscopic curative resection for duodenal adenocarcinoma. The histological structure of the elevation was identified as a minor papilla because it showed Santorini’s duct surrounded by sphincters beneath the submucosa (Fig. 2). We successfully performed a complete resection of a rare duodenal adenocarcinoma covering the minor papilla without severe adverse events. Injury to the minor papilla in cases with pancreas divisum can be fatal. When endoscopically treating a lesion on the medial wall of the descending part of the duodenum, it is preferable to confirm the location of the minor papilla and the presence or absence of a pancreas divisum. Authors declare no conflict of interest for this article.