Pancreatic Adenocarcinoma Invading the Duodenum and Presenting as Idiopathic Gastroparesis with Nausea and Vomiting

A 65-year-old woman presented with a 5-month history of nausea, vomiting, and weight loss. Prior esophagogastrodudenoscopy showed retained food and delayed gastric emptying, but abdominal computed tomography was normal. The working diagnosis was idiopathic gastroparesis. Subsequently, an electrogastrogram test showed normal 3-cycle-per-minute activity, although it was suggestive of obstructive gastroparesis. Repeat esophagogastrodudenoscopy showed obstruction at the postbulbar duodenum. Repeat abdominal computed tomography revealed a 2.2 x 1.6-cm mass in the pancreaticoduodenal groove narrowing the descending duodenum and aspiration of the mass revealed adenocarcinoma.