A pancreatic islet cell tumor is an uncommon tumor of the pancreas that arises from a distinct type of cell in the pancreas, the islet cell. Normally, islet cells produce insulin and other hormones, and islet cell tumors can also produce hormones.

Alternative Names

Islet cell tumors; Islet of Langerhans tumor; Neuroendocrine tumors

Causes, incidence, and risk factors

In the normal pancreas, cells called islet cells produce hormones that regulate a variety of bodily functions, such as blood sugar level and the production of stomach acid. Tumors that arise from islet cells of the pancreas can also produce a variety of hormones, though some do not. Although islet cells produce many different hormones, most tumors secrete only one specific hormone that leads to specific symptoms. Pancreatic islet cell tumors can be benign or malignant (cancerous). Islet cell tumors include insulinomas, glucagonomas, and gastrinomas ( Zollinger-Ellison syndrome ). A family history of multiple endocrine neoplasia, type I ( MEN I ) is a risk factor for the development of islet cell tumors.

Signs and tests

The type of tests performed may vary depending upon the symptoms associated with the condition. Some of the following abnormalities may be detected on testing:

elevated

serum glucagon level

an

abdominal CT scan may reveal a pancreatic tumor (sometimes the tumor may be too small to see with a CT scan)

elevated

fasting glucose level

abnormal

glucose tolerance test

catheterization of the pancreas to show high

hormone level in the veins (this involves putting a wire into a blood vessel and taking blood out for measurements)

MRI of abdomen

to show pancreatic tumor (MRI can sometimes see smaller tumors than those seen with a CT scan)

elevated serum insulin level

elevated

serum insulin C-peptide

low fasting glucose level

increased

gastrin level

positive

secretin stimulation test for pancreas

positive calcium infusion test

Treatment

Treatment will depend upon the type of tumor discovered and whether the tumor is benign or malignant. Malignant tumors spread to other organs, grow aggressively, and may not be treatable. In general, tumors are removed surgically, if possible. If malignant cancerous cells spread (metastasize) to the liver, a portion of the liver may also be removed, if possible. If the cancer is widespread, various forms of chemotherapy may be used to shrink the tumors. If the abnormal production of hormones is causing problems, medications may be given to counteract their effects. For example, the overproduction of gastrin in the case of gastrinomas results in oversecretion of acid in the stomach, and medications that block acid secretion can be taken to reduce symptoms.

Expectations (prognosis)

Patients may be cured if tumors are surgically removed before they have spread to other organs. If tumors are malignant, chemotherapy may be used, but is usually unsuccessful at curing patients. Death may result from serious problems due to excess hormone production (hormone crises), such as very low blood sugar or from widespread metastasis .

Complications

Metastasis (spread) of the tumor to the liver can occur. Hormone crises can occur, depending on whether the cells that make up the tumor secrete hormones and what type of hormones are made. Gastrinomas can induce severe ulcers in the stomach and small intestine.

Calling your health care provider

Call your health care provider if symptoms of this tumor develop, especially if you have a family history of MEN1.

Prevention

There is no known prevention for these tumors.