Intussuscepting Ampullary Adenoma: An Unusual Cause of Gastric Outlet Obstruction Leading to Cavitating Lung Lesions

Ampullary adenomas are a rare clinical entity, occurring at a rate of 0.04-0.12% in the general population. They are premalignant lesions which have the capability to progress to malignancy, and they should be excised if they are causing immediate symptoms and/or are likely to degenerate to carcinoma. Intestinal intussusception in adults is rare and, unlike in children, is often due to a structural pathology. Intussuscepting duodenal/ampullary adenomas have been reported in the literature on 13 previous occasions, however never before with this presentation. We report the case of a woman who presented with a 1-year history of recurrent chest infections. She was treated with numerous antibiotics, whilst intermittent symptoms of recurrent vomiting and weight loss were initially attributed to her lung infections. A chest CT demonstrated multiple cavitating lung lesions, whilst an obstructing polypoid mass was noted at D2 on dedicated abdominal imaging. Due to ongoing nutritional problems, she had a semi-urgent pancreaticoduodenectomy. Intraoperative findings demonstrated a large mass at D2 with a duodeno-duodenal intussusception. Histological analysis reported a duodenal, ampullary, low-grade tubular adenoma, 75 × 28 × 30 mm in size, with intussusception and complete resection margins. The patient recovered well and was discharged on postoperative day 10, with no complications to date. Ampullary adenomas may present with obstruction of the main gastrointestinal tract and/or biliary/pancreatic ducts. Common presentations include gastric outlet obstruction, gastrointestinal bleeding or acute pancreatitis. This unique presentation should remind clinicians of the need to investigate recurrent chest infections for a possible gastrointestinal cause.