Pancreatic neuroendocrine tumours

Pancreatic neuroendocrine tumours are rare tumours (similar to 1/100,00 population/year) of which 60% are non-functioning. Except for insulinoma all types are malignant in > 50% of cases. In multiple endocrine neoplasia (MEN)I, pancreatic neuroendocrine tumours occur in 40-80% of patients and are mostly non-functioning tumours or gastrinomas. Insulinomas are benign in similar to 90%, solitary in 95% of sporadic cases whilst multiple in 90% of MEN I patients. In contrast similar to 50% gastrinomas and the majority of non-functioning pancreatic neuroendocrine tumours are malignant. Pancreatic neuroendocrine tumours occur in 10-15% of patients with Von Hippel-Lindau (VHL) and are frequently multiple (> 30%). Surgical excision is a key aspect of treatment for all cases of sporadic gastrinoma and if > 2.5 cm in MEN I. Insulinomas are enucleated if solitary and may require pancreatectomy if multiple. Non-functioning tumours should also be resected if sporadic and if > 2 cm in MEN I or if > 2-3 cm in VHL. Tumours < 1 cm require yearly follow-up by CT or MRI from an early age in VHL. The local treatment for liver metastases is now well established and options include liver resection, chemoembolisation and radiofrequency ablation. Systemic therapies have also been better defined and include radionuclide therapy against somatostatin receptors or MIBG and chemotherapy especially for poorly differentiated tumours. A number of novel agents are currently in clinical development.