Glucagonoma

Definition

Glucagonoma is a tumor of the islet cells of the pancreas, which secrete the hormones insulin and glucagon.

Causes, incidence, and risk factors

Glucagonoma is usually malignant (cancerous). The cancer tends to spread and get worse. The cancer affects the islet cells of the pancreas. As a result, they produce too much of a hormone called glucagon.

The excess glucagon causes symptoms such as glucose intolerance and hyperglycemia (elevated blood sugar). Spreading of the cancer (metastasis) to the liver may occur. Glucagonoma also cause a distinctive skin lesion called necrolytic migratory erythema.

The cause is unknown, but genetic factors play a role in some cases. Risk factors include a family history of multiple endocrine neoplasia type I (MEN I).

Symptoms

• Skin rash that migrates on face, abdomen, perineum, buttocks, or lower extremities
  • May be crusty or scaly
  • May be raised lesions filled with clear fluid or pus
• Inflamed mouth and tongue
• Unintentional weight loss
• Excess thirst
• Frequent urination
• Nocturnal (nighttime) urination
• Increased appetite

Signs and tests

• Higher than normal serum glucagon level
• Pancreatic tumor revealed by CT scan
• Higher than normal fasting glucose level
• Abnormal glucose tolerance test

Treatment

Surgical removal of the tumor is the preferred treatment. The tumor does not respond to chemotherapy.

Expectations (prognosis)

Approximately 60% of these tumors are cancerous. Metastasis (spread) to the liver is common.

Complications

Metastasis of cancer to the liver is a complication.

Calling your health care provider

Call your health care provider if you notice symptoms suggestive of glucagonoma.