Definition of Pancreatic neuroendocrine tumors (pancreatic NETs)

Pancreatic neuroendocrine tumors (pancreatic NETs, PNETs): a type of tumor that arises from hormone-producing cells in the pancreas. Pancreatic NETs may be either benign or malignant and may produce hormones (termed a "functional" pancreatic NET) or not produce hormones (a "nonfunctional" pancreatic NET). Often, the tumor itself does not produce signs or symptoms, although the hormones produced by the tumor may cause symptoms.

• The main types of functional pancreatic NETs are gastrinoma, insulinoma, and glucagonoma. These produce the hormones gastrin, insulin, or glucagon, respectively. Most glucagonomas and gastrinomas are malignant, while most insulinomas are benign. Nonfunctional tumors also tend to be malignant.
• Other types of functional pancreatic NETs include tumors that produce vasoactive intestinal peptide (VIPomas) and somatostatinomas.
• Having the condition known as multiple endocrine neoplasia 1 syndrome (MEN1) increases the risk of developing a pancreatic NET.
• Some of the symptoms produced by the different kinds of pancreatic NETs include changes in hypoglycemia, diarrhea, stomach ulcers, dehydration, and weight loss, although the specific symptoms vary according to the type of hormone made by the tumor.
• There are a number of possible treatments, including surgery, chemotherapy, hormone therapy, and targeted therapy.