[A Case of Non-Functioning Pancreatic Neuroendocrine Tumor Accompanied by Stenosis of the Main Pancreatic Duct].

We experienced a rare case of pancreatic neuroendocrine tumor(pNET)in which stenosis of the main pancreatic duct occurred despite the tumor diameter being less than 1 cm; therefore, here, we report this case with some literature review.A 41-year-old woman showed dilation of the main pancreatic duct on an abdominal ultrasound as part of a health examination, and she visited our department for a more detailed examination.Enhanced CT scan showed a 7mm subtle enhancing mass in the head of the pancreas and the upstream main pancreatic duct was dilated up to 7 mm.ERCP and MRCP images also showed a dilated main pancreas duct.We suspected that her tumor was a pNET.We decided not to perform surgery immediately. After 6 months of follow-up, the tumor size increased to 10 mm; therefore, we performed subtotal stomach-preserving pancreaticoduodenectomy considering the possibility of pancreatic cancer.Histopathological findings showed that the pancreatic tumor had the property of a neuroendocrine tumor and the proliferated fibrous stroma around it caused the pancreas duct stenosis.