Carcinoid tumor of the minor papilla in complete pancreas divisum presenting as recurrent abdominal pain

BACKGROUND Tumors of the minor papilla of the duodenum are extremely rare, and they are mostly neuroendocrine tumors, such as somatostatinomas and carcinoid tumors. However, true incidence of carcinoid tumors in minor papilla might be much higher, because patients with minor papillary tumors usually remain asymptomatic. We report a very unusual case of carcinoid tumor in a patient with complete pancreas divisum with a review of the literature. CASE PRESENTATION A 56-year-old female patient was referred for evaluation of pancreatic duct dilatation noted on abdominal ultrasonography and computerized tomography. She complained of intermittent epigastric pain for 6 months. A MRCP and ERCP revealed complete pancreas divisum with dilatation of the main pancreatic duct. On duodenoscopy, a small, yellows, subepithelial nodule was visualized at the minor papilla; biopsy of this lesion revealed a carcinoid tumor. She underwent a pylorus-preserving pancreaticoduodenectomy. The histologic evaluation showed a single nodule, 1 cm in diameter, in the submucosa with duodenal and vascular invasion and metastasis to the regional lymph nodes. CONCLUSION Although the size of the carcinoid tumor was small and the tumor was hormonally inactive, the concomitant pancreas divisum led to an early diagnosis, the tumor had aggressive behavior. Carcinoid tumors of the minor papilla should be included in the differential diagnosis of recurrent abdominal pain or pancreatitis of unknown cause.