Islet cell tumors

Definition

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

Alternative Names

Causes

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

Symptoms

• Sweating
• Tremor
• Rapid heart rate
• Anxiety
• Hunger
• Dizziness
• Headache
• Clouding of vision
• Confusion
• Behavioral changes
• Convulsions
• Loss of consciousness
• Skin rash that migrates on the face, abdomen, perineum, buttocks, or lower extremities
  • May be crusty and scaly
  • May have raised lesions filled with clear fluid or pus
• Inflamed mouth and tongue
• Weight loss
• Weight gain (unintentional)
• Peptic ulcer pain
• Vomiting blood
• Diarrhea
• Abdominal pain

Note: The symptoms depend upon the type of tumor and the hormone produced.

Exams and Tests

The type of tests performed may vary depending upon the symptoms associated with the condition. The following tests may be performed:

• An abdominal CT scan  (sometimes the tumor may be too small to see with a CT scan)
• MRI of abdomen (MRI can sometimes see smaller tumors than those seen with a CT scan)
• Gucose tolerance test
• Fasting glucose level
• Serum insulin C-peptide
• Serum insulin level
• Gastrin level
• Secretin stimulation test for pancreas
• Fasting glucose level
• Serum glucagon level
• Abdominal ultrasound
• Endoscopic ultrasound
• Intraductal endoscopic ultrasound
• Sampling of the venous drainage of segments of the pancreas
• Occasionally, the diagnosis and treatment requires exploratory surgery, during which the surgeon feels the pancreas and may use ultrasound probes

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.

Outlook (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, such as very low blood sugar, or from widespread metastasis.

Possible 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. Insulinomas can cause severe hypoglycemia (low blood sugar).

When to Contact a Medical Professional

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.