Surgical treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNET) exhibit a variety of symptoms at the clinical setting depending on the hormone that is secreted by the tumor. Accordingly, a wide range of tumor types exist for pNETs, but it is assumed that enterochromaffin cells in the neuroendocrine tissue are the origin of all tumors. Diagnostic methods cannot be standardized because the symptoms are different for each type of tumor. On the other hand, an indication for surgical resection should be always considered if a pNET is encountered. Risks of metastasis and recurrence are very high in tumors other than insulinomas; therefore lymph node dissection is necessary. Even if the tumor is accompanied by liver metastasis, one should consider whether a liver resection would provide a clinical benefit or not. Molecular targeted therapy for pNET is recently available in Japan. Because it is not always possible to achieve curative surgical resection, combined modality therapy should be considered.