Mixed serous-neuroendocrine neoplasm of the pancreas: A case report and review of the literature.

Background: Pancreatic mixed serous-neuroendocrine neoplasms (MSNNs) are mixed tumors containing two components with different pathologies, namely, pancreatic serous cystic neoplasm (PSCN) and pancreatic neuroendocrine tumor (PanNET). For MSNNs, diffuse PSCN involving the whole pancreas is extremely rare, with only eight previous case reports.

Case Summary: A 45-year-old Chinese woman, with a free previous medical history and no obvious symptoms, was found to have a pancreatic neoplasm and admitted to our hospital for further diagnosis in March 2018. Abdominal palpation revealed a painless, mobile mass in the epigastrium, and no abnormalities were observed in an examination of the nervous system and ocular system. A computed tomography scan showed multiple cystic lesions involving the whole pancreas ranging in diameter from 0.4 to 2 cm and also revealed an enhanced mass, 2.2 cm in diameter, in the head of the pancreas. Moreover, multiple cysts were found in the kidneys bilaterally, and the right lobe of the liver contained a small cyst. A Whipple operation with total pancreatectomy and splenectomy was performed. A diagnosis of pancreatic MSNN was established, consisting of diffuse serous microcystic cystadenoma with a concomitant grade 2 PanNET. Of note, the patient had no personal or family history of Von Hippel-Lindau syndrome or other disease.

Conclusion: We report the first case of MSNN with a diffuse PSCN component involving the entire pancreas in a Chinese woman. It is important to be aware of its relationship with VHL syndrome, and close clinical follow-up is recommended.