Islet cell tumors; Islet of Langerhans tumor; Neuroendocrine tumors

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 release only one hormone that leads to specific symptoms. Pancreatic islet cell tumors can be noncancerous (benign ) or cancerous (malignant).

Islet cell tumors include:

• Gastrinomas (Zollinger-Ellison syndrome )
• Glucagonomas
• Insulinomas

A family history of multiple endocrine neoplasia, type I (MEN I ) is a risk factor for islet cell tumors.

Symptoms are caused by the hormone the tumor is producing. For example, an insulinoma may produce too much insulin, leading to very low blood sugar levels.

Symptoms can include:

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

Tests may vary depending upon the symptoms. The following tests may be performed:

• Abdominal CT scan
• Abdominal ultrasound
• Endoscopic ultrasound
• Fasting glucose level
• Gastrin level
• Gucose tolerance test
• Intraductal endoscopic ultrasound
• MRI of abdomen
• Sampling the vein drainage of segments of the pancreas
• Secretin stimulation test for pancreas
• Serum glucagon level
• Serum insulin C-peptide
• Serum insulin level

Occasionally, surgery is needed to diagnose and treat this condition. During this procedure, the surgeon feels the pancreas and may use ultrasound probes.

Treatment will depend on the type of tumor and whether the tumor is noncancerous (benign) or cancerous (malignant). Malignant tumors can spread to other organs, grow aggressively, and may not be treatable. Tumors are usually removed with surgery, if possible.

If malignant cancer 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, you may receive medications to counteract their effects. For example, with gastrinomas, the overproduction of gastrin leads to too much acid in the stomach. Medications that block acid release can reduce symptoms.

You may be cured if the tumors are surgically removed before they have spread to other organs. If tumors are cancerous, chemotherapy may be used, but it usually cannot cure patients.

Life-threatening problems (such as very low blood sugar) can occur due to excess hormone production, or if the cancer spreads throughout the body.

• Hormone crises (if the tumor releases certain types of hormones)
• Severe low blood sugar (from insulinomas)
• Severe ulcers in the stomach and small intestine (from gastrinomas)
• Spread of the tumor to the liver

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

There is no known prevention for these tumors.