THE SURGICAL MANAGEMENT OF PANCREATIC NEUROENDOCRINE TUMORS

Neuroendocrine tumors (NETs) of the pancreas are rare pancreatic NET tumors that arise from the islet cells of Langerhan. There are approximately 2500 cases of pancreatic islet cell tumors in the United States per year. Most pancreatic NETs are “nonfunctional” and are discovered incidentally during imaging studies performed for other reasons. Occasionally, pancreatic NETs are identified when imaging studies are performed for nonspecific abdominal pain or in the course of a workup for biliary or bowel obstruction.

As many as half of these tumors secrete one or more biologically active peptides, which may result in the development of one of five phenotypically distinct clinical syndromes: (1) the insulinoma syndrome,⁹² (2) the gastrinoma syndrome,⁹⁵ (3) the WDHA syndrome,⁸⁸ (4) the glucogonoma syndrome,⁴⁶ and (5) the somatostatinoma syndrome.²¹ Although initial features of these clinical syndromes may be discrete and nonspecific, in most patients, severe and often life-threatening complications eventually develop as a result of excessive hormone production. Moreover, many of these tumors are malignant and often metastasize to the liver, resulting in death. Uniquely, despite the presence of metastatic liver disease, pancreatic NETs generally follow an indolent course and prolonged survival is common. In addition to the tumors producing the earlier-mentioned clinical syndromes, a significant proportion of the NETs of the pancreas are not associated with hormone overproduction.³⁷

With increasing reliance on diagnostic imaging in medicine, pancreatic NETs are being recognized with increasing frequency. In this issue, Brentjens and Saltz extensively discuss the clinical presentation, natural history, and medical management of the various types of pancreatic NETs (see pages 527–542). This article focuses solely on concepts important in the surgical management of “functional” and “nonfunctional” islet cell tumors.