Case Presentation: Bouveret Syndrome is a rare complication of gallstone disease and is critical to recognize early, given its 60% morbidity rate and 30% mortality rate. We present a unique case of Bouveret syndrome causing duodenal adenocarcinoma. A 73-year-old male presented to the ER with chief complaints of abdominal pain, nausea, and vomiting for 2 days. CT abdomen and pelvis with contrast showed soft tissue thickening and luminal irregularity at the pylorus and duodenal bulb. Gastroenterology was consulted for gastric outlet obstruction, and esophagogastroduodenoscopy revealed a large, solid bezoar impacted in the duodenal bulb with erosions and ulcerations. The bezoar could not be extricated with standard or therapeutic scopes or with multiple endoscopic tools. However, on repeat EGD, the bezoar was successfully dislodged and sent into the small bowel. Subsequently, the patient was put on a high-dose proton-pump inhibitor and Carafate for mucosal healing; however, the abdominal pain continued, and a CT abdomen revealed an SBO in the right lower quadrant. He then underwent a diagnostic laparotomy, which was converted to a small bowel resection, where the gallstone was also removed. Postoperatively, he did well with the resolution of abdominal pain and the passage of flatus. Six weeks later, he underwent a follow-up EGD for the duodenal ulcerations. During the EGD, he was noted to have a nodular mass in the duodenum, which showed villous architecture and dysplastic glandular epithelium, and the surgical pathology revealed “at least an adenocarcinoma in situ” arising from an adenomatous polyp. Following this EGD, the patient underwent an EUS, which revealed a malignant-appearing mass in the posterior wall of the duodenum. After a failed ERCP, he subsequently underwent surgical resection and lymph node biopsy. Final pathology revealed invasive adenocarcinoma, moderately differentiated, arising in the duodenal bulb, with 0/7 biopsied lymph nodes involved. The patient did well post-operatively, and several months later, colonoscopy was negative and only revealed two small hyperplastic polyps.
Discussion: This case represents a rare and clinically significant complication of Bouveret syndrome. The patient’s longstanding cholecystitis led to chronic inflammation and the eventual formation of a cholecystoduodenal fistula, allowing the gallstone to migrate into the proximal duodenum. The resulting gastric outlet obstruction produced persistent mucosal irritation and dystrophic changes, ultimately contributing to malignant transformation and the development of duodenal adenocarcinoma.
Conclusions: Current management of Bouveret Syndrome with endoscopy serves as first-line therapy due to its diagnostic and therapeutic potential, while surgical intervention is reserved for high-risk features. Bouveret Syndrome most commonly presents as a mechanical obstruction, however this case highlights the importance of recognizing the long-term oncologic implications of chronic biliary–enteric fistulas.