Information on Insulinoma

Insulinoma involves the beta cells in the pancreas of the ferret that develop into tumor, and is unfortunately fairly common in ferrets aged 2-4 and up. It is this tumor(s) that causes the excess production of insulin. High insulin levels cause low blood sugar levels. They usually occur as single, small tumors in adults. They are very rare in children. Most children with hyperinsulinism have multiple areas of overactive insulin-secreting cells in the pancreas, rather than a single tumor. Most insulinomas are benign only 5 to 10 percent are cancerous.

People with the genetic syndrome called multiple endocrine neoplasia Type I (MEN I) are at risk for developing insulinomas. The typical symptoms that patients complain about are related to the development of low bloods sugar and include tiredness, weakness, tremulous and hunger. The low levels of sugar in the blood may even lead to a loss of consciousness, seizures, and coma. Surgery is the normal treatment for insulinoma. Surgical removal of the tumor is the treatment of choice. More than 90% of patients will not require any further treatment after removal of the tumor. Tumors may be solitary or multiple.

Solitary tumors are removed, but patients with multiple tumors usually need partial removal of the pancreas. Octreotide is used to suppress insulin secretion in some patients. Medication is also used to alleviate the patient prior to surgery. Medications such as diazoxide and somatostatin can be used to block the release of insulin for patients who are not surgical candidates or who otherwise have inoperable tumours. Streptozotocin is used in islet cell carcinomas which produce excessive insulin. Prednisone is usually the first drug used, with a typical dosage range of 0.5 - 2.5 mg/kg twice a day.

High doses of proton pump inhibitors may be effective for reducing acid levels and relieving symptoms temporarily. If no tumor can be found, or if the patient is not a candidate for surgery, the drug diazoxide may be given to lower insulin secretion and avoid hypoglycemia. If cancerous tumors have spread to other parts of the body, chemotherapy may help reduce the number of tumor cells and the levels of gastrin in the blood. However, such therapy does not cure the cancer, which is ultimately fatal. Exercise may aggravate hypoglycemia in patients with insulinoma.