Brunner's Gland Hyperplasia Causing Gastric Outlet Obstruction and Mimicking Malignancy

Brunner gland hyperplasia (BGH) is a benign proliferative lesion of the duodenum that may mimic malignant disease on imaging and endoscopic evaluation. Large lesions may present with obstructive symptoms. We report a 41-year-old man with recurrent epigastric pain and postprandial vomiting secondary to gastric outlet obstruction. Serial computed tomography examinations demonstrated progressive radiologic changes from a possible obstructing lesion or intussusception to an ill-defined 5.5 × 4.2-cm pyloroduodenal mass with loss of the fat plane between the duodenum and pancreas and associated lymphadenopathy. Endoscopic biopsies obtained during two admissions one year apart demonstrated benign Brunner gland hyperplasia without dysplasia or carcinoma. This case illustrates the diagnostic discordance that may occur between suspicious imaging and persistently benign biopsy findings in a predominantly submucosal lesion. Endoscopic ultrasound with deep tissue acquisition may improve lesion characterization; however, persistent symptomatic obstruction or inability to exclude malignancy may necessitate definitive intervention.