Pancreatic Neuroendocrine Tumors (Islet Cell Tumors) Treatment (PDQ®): Treatment - Patient Information [NCI] - General Information About Pancreatic Neuroendocrine Tumors (Islet Cell Tumors)
Pancreatic neuroendocrine tumors form in hormone-making cells (islet cells) of the pancreas.
The pancreas is a gland about 6 inches long that is shaped like a thin pear lying on its side. The wider end of the pancreas is called the head, the middle section is called the body, and the narrow end is called the tail. The pancreas lies behind the stomach and in front of the spine.
Anatomy of the pancreas. The pancreas has three areas: head, body, and tail. It is found in the abdomen near the stomach, intestines, and other organs.
There are two kinds of cells in the pancreas:
- Endocrine pancreas cells make several kinds of hormones (chemicals that control the actions of certain cells or organs in the body), such as insulin to control blood sugar. They cluster together in many small groups (islets) throughout the pancreas. Endocrine pancreas cells are also called islet cells or islets of Langerhans.
- Exocrine pancreas cells make enzymes that are released into the small intestine to help the body digest food. Most of the pancreas is made of ducts with small sacs at the end of the ducts, which are lined with exocrine cells. This summary discusses islet cell tumors of the endocrine pancreas. See the PDQ summary on Pancreatic Cancer Treatment for information on exocrine pancreatic cancer.
A pancreatic neuroendocrine tumor (NET) may also be called a pancreatic endocrine tumor (PET), islet cell tumor, islet cell carcinoma, or pancreatic carcinoid.
Pancreatic NETs are much less common than pancreatic exocrine tumors and have a better prognosis.
Pancreatic NETs may or may not cause symptoms.
Pancreatic NETs may be functional (the hormones that are released cause symptoms) or nonfunctional (the hormones that are released do not cause symptoms) tumors:
- Functional tumors make one or more hormones, such as gastrin, insulin, and glucagon, that cause symptoms. Most functional tumors are benign (not cancer).
- Nonfunctional tumors make substances that do not cause symptoms. Symptoms are caused by the tumor as it spreads and grows. Most nonfunctional tumors are malignant (cancer).
Most pancreatic NETs are functional tumors.