[A case of pancreatic neuroendocrine tumor presenting with main pancreatic duct invasion].

A 52-year-old male visited a local clinic with a subjective complaint of pain in the left side of his abdomen. Abdominal CT revealed the presence of a pancreatic body tumor. On EUS, the tumor presented hypoechoic signals with an obscure boundary, which continued from the pancreatic parenchyma to the inside of the main pancreatic duct. Abdominal contrast CT revealed a hypervascular tumor with densely stained pancreatic parenchyma. ERP findings revealed that main pancreatic duct invasion was suspected based on partial radiolucency in the duct. Distal pancreatectomy was performed, and a definitive diagnosis of pancreatic neuroendocrine tumor (WHO class G1) was made histopathologically.