A Rare Case of Ampullary Carcinoma with Complete Duodenal Obstruction as the Initial Manifestation.

Introduction: Obstructive jaundice is often the first symptom of ampullary carcinoma, with a straightforward preoperative diagnosis. We report a rare case of ampullary carcinoma without jaundice as the initial symptom.

Case presentation: A 53-year-old man was admitted with abdominal distension and recurrent vomiting. Esophagogastroduodenoscopy revealed a complete duodenal obstruction without malignant findings. Computed tomography revealed wall thickening in the second portion of the duodenum. The common bile duct and main pancreatic duct were not dilated. As there was no evidence of malignancy, we performed gastrojejunostomy as a bypass to improve the symptoms. Five months later, follow-up blood examinations showed elevated total bilirubin levels, and computed tomography revealed persistent thickening of the duodenal wall with exacerbated dilation of common bile duct and main pancreatic duct. Mucosal biopsies from the oral and anal sides of the stenosis revealed no malignancy. Due to a strong suspicion of malignant disease and difficulty in preoperative biliary drainage, we performed pancreatoduodenectomy. Pathological examination revealed mucinous adenocarcinoma with submucosal and subserosal invasion of the duodenum. We finally diagnosed this case as ampullary carcinoma.

Conclusions: The possibility of malignancy should be considered even in cases of duodenal obstruction that have not been diagnosed as malignant after repeated close examination.