Insulinoma

The cause of an insulinoma is unknown.

There are few risk factors for an insulinoma. But, women seem to be affected more often than men. Most often, it starts between ages 40 and 60. Some genetic diseases can raise your chance of getting an insulinoma. They are:

• Multiple endocrine neoplasia type 1, abnormal tissue growth in the endocrine system.
• Von Hippel-Lindau syndrome, an inherited disease that causes tumors and cysts throughout your body.
• Other genetic syndromes, such as neurofibromatosis type 1 and tuberous sclerosis.

An insulinoma can cause these symptoms:

• Confusion.
• Sweating.
• Weakness.
• Rapid heartbeat.

If your blood sugar gets too low, you can pass out and even go into a coma.

Insulinomas are rare and can be difficult to diagnose. Some data show the average time from the start of symptoms to diagnosis is about a year and a half.

If your healthcare provider thinks you have an insulinoma, you may stay in the hospital for a few days. This is so your healthcare provider can watch your blood sugar and other substances in your blood while you fast. You will not be able to eat or drink anything except water during this time. If you have an insulinoma, you will probably have very low blood sugar levels within 48 hours of starting this test. If your symptoms of low blood sugar have been after meals, you may have a test of your blood sugar and insulin for several hours after a meal.

You may also have imaging tests. These can help find out how big your tumor is and where it's located. A transabdominal ultrasound study is usually the first test done. Other tests include endoscopic ultrasound, CT scan or MRI. If the insulinoma is too small to be seen with these imaging tests, you may need tests that sample blood from multiple areas of your pancreas. These will find where the extra insulin is being released into your bloodstream.

Most insulinomas are not cancer. A surgeon can usually remove it and cure the condition. This may be done using a laparoscope. In laparoscopy, the surgeon makes small incisions and uses special small tools to remove the tumor. If your healthcare provider thinks that surgery would not be a good option for you, there are other options. These would help the symptoms of hypoglycemia. For example, you may need to eat small, frequent meals and taking some medicines to fight the effects of excess insulin.

While you are waiting for your surgery, you may stay in the hospital and get intravenous (IV) solutions to keep you from becoming hypoglycemic.

After surgery to remove an insulinoma, some people develop a pancreatic fistula. This causes pancreatic fluid to leak. You may be given medicine and extra fluids to help your fistula heal. Most close without the need for more surgery.

There are no known ways to prevent an insulinoma. You may want to be checked for an insulinoma if any of your family members have any of the genetic conditions that increase risk.

Almost all insulinomas are not cancer. Removing the tumor cures the condition. Usually, symptoms don't recur. You are unlikely to get diabetes unless your surgeon has to remove a large part of your pancreas.

A small number of insulinomas are cancer. Your surgeon may not be able to remove them entirely. If this happens, you may need to take medicine to help prevent hypoglycemia. You may also need chemotherapy to help control the size of your tumor.

If you have an insulinoma, you may have symptoms of low blood sugar. These include sweating, confusion, and double vision. You may notice these symptoms more when you’re hungry or after exercise. If you have these symptoms several times in 1 week, talk to your healthcare provider right away.