Management of Small Nonfunctional Pancreatic Neuroendocrine Tumors

Abstract

Pancreatic neuroendocrine tumors (PNETs) are rare, accounting for only 2 % of pancreatic tumors. Traditional dogma dictates that nonfunctional PNETs are static in size and a correlation between size and malignant potential exists. However, improvements in radiographic technology have pointed to the contrary. Modern imaging is responsible for a rising incidence of PNET diagnoses and for observations that even small tumors may grow. With a steep rise in the diagnosis of small PNETs, the controversial question in modern hepatopancreaticobiliary surgery of appropriate management for small nonfunctional PNETs has never been more important, and this chapter explores the role of surgery.

The small size of incidental, nonfunctional PNETs may belie metastatic potential. Review of the data does not guarantee that small size precludes metastasis and clear predictors of malignant potential are not consistently defined. There is moderate evidence that supports that surgical resection, as opposed to observation, should remain the standard of care. Future prospective studies, a constellation of biomarkers, or genetic findings may improve prognostication to supplement histopathology and better aid in a selective treatment approach. Special consideration to a nonsurgical approach should be afforded to patients with poor lifetime expectancy or those with cancer susceptibility syndromes that include Multiple Endocrine Neoplasia Type 1, von Hippel-Lindau disease, neurofibromatosis Type 1, and tuberous sclerosis.