[A Resected Case of Neuroendocrine Tumor of the Minor Papilla of Duodenum].

The patient was a 67-year-old woman. She was referred to our gastroenterology department after pancreatic duct dilatation was found on abdominal ultrasound by her family doctor. After detailed examination, she was diagnosed with neuroendocrine neoplasm(NEN)of the minor papilla of duodenum, and pancreaticoduodenectomy with lymph node dissection was performed. Histopathological examination revealed invasive tumor growing from the mucosal epithelium to the muscularis propria of the duodenum. The tumor was composed of cells with small, round nuclei. The tumor cells were positive for synaptophysin, chromogranin A, and CD56, and the Ki-67 index was less than 1%. Based on the above, we diagnosed the tumor as neuroendocrine tumor(Grade 1)of the minor papilla of duodenum. In addition, metastasis to the anterior lymph nodes of the pancreatic head was observed. The patient is currently alive and free of recurrence 4 years after surgery. NEN is a tumor that occurs throughout the body, but those that occur in the minor papilla are rare. Because NEN arising from the minor papilla of duodenum has a high rate of lymph node metastasis, pancreaticoduodenectomy with lymph node dissection is recommended.