[Surgical strategies for small sporadic neuroendocrine pancreatic tumors].

Small (<2 cm) sporadic neuroendocrine pancreatic neoplasms (pNENs) are a heterogeneous group of neoplasms, which can be separated into functionally active or non-functional tumors. Functionally active pNENs release various hormones, such as insulin, gastrin, glucagon and vasoactive intestinal hormones and therefore lead to severe symptoms independent of their size. The main symptoms include hypoglycemia, coma (insulinoma), diarrhea (gastrinoma, VIPoma), intestinal ulcers (gastrinoma) and hyperglycemia (glucagonoma). Asymptomatic inactive pNENs do not cause a hormonal syndrome even though in immunohistochemistry they are positive for various hormones and endocrine markers (e.g. chromogranin and synaptophysin). Non-active small pNENs are increasingly being found because of the widespread use of high-resolution imaging and are named incidental pNENs. The current therapy algorithms of small functionally active and non-functional pNENs are very different and include besides non-operative management and surveillance (wait and see strategy) of non-active pNENs (G1, low G2), all minimally invasive, open and robotic techniques of pancreas resection. Until today almost all recommendations of surgical and nonsurgical therapy algorithms have been established based on retrospective data.