Clinical characteristics of pancreatic neuroendocrine tumors in Japanese patients with von Hippel-Lindau disease

Objective: The aim of this study was to elucidate the clinical characteristics of pancreatic neuroendocrine tumors (NET) in Japanese patients with von Hippel-Lindau (VHL) disease. Methods: We sent a questionnaire to all members of the Japan Pancreas Society in 2002 asking for the number of patients with VHL and complications of NET and/or cystic lesion in the pancreas. Furthermore, we sent a second questionnaire to obtain detailed information about the clinical characteristics of pancreatic NET. Results: A total of 58 patients with VHL were reported. Among these, 34 (59%) patients had pancreatic lesions, including 10 with pancreatic NET, 23 with a cystic lesion, and one with both. The mean age at identification of pancreatic NET was 34.6 years (range, 22-64 years). The mean diameter of the tumors was 4.3 cm (range, 1-12.5 cm). Distant metastases were found in 2 (20%) cases. During the follow-up period (3.3 years; range, 0-8 years), 7 patients are alive, and 2 patients died of hemangioblastomas. Conclusions: Pancreatic NET in the VHL disease showed a relatively lower incidence of metastasis compared with sporadic non-functioning pancreatic NET, yielding a favorable prognosis. Because they present no hormonal syndrome, periodic screening examinations are warranted to identify pancreatic NET at an early stage.