Asian Journal of Case Reports in Surgery

Brunner's gland hyperplasia is a rare benign proliferative lesion of the duodenal submucosa that occasionally presents as a periampullary mass with biliary obstruction, closely mimicking carcinoma. We report a 70-year-old woman who presented with recurrent upper abdominal pain without jaundice, weight loss or gastrointestinal bleeding. Ultrasonography showed marked dilatation of the common bile duct with intrahepatic biliary radicle dilatation. Cross-sectional imaging with contrast-enhanced computed tomography and magnetic resonance cholangiopancreatography revealed a heterogeneously enhancing periampullary lesion measuring approximately 10 × 10 × 14 mm involving the distal common bile duct, ampulla and medial duodenal wall. The pancreatic duct measured approximately 4 mm producing a classical double-duct sign strongly suggestive of periampullary carcinoma. In view of these findings, the patient underwent pancreaticoduodenectomy. Histopathological examination of the resected specimen revealed Brunner’s gland hyperplasia without dysplasia or malignancy. Although nearly 200 cases of Brunner’s gland hyperplasia have been reported worldwide, periampullary localisation producing biliary obstruction and a double-duct sign is exceptionally uncommon and may closely mimic periampullary carcinoma, occasionally leading to radical surgery. This case highlights an important diagnostic pitfall and discusses imaging clues that may help differentiate benign periampullary lesions from malignancy.