Insulinoma Support Network

Tests for insulinomas

Testing for insulinomas

Some tests for insulinomas you might undergo include:

Biopsy  This involves taking a piece of tissue from the suspect tumour and having it analysed in the laboratory by a specialist called a histopathologist. Biopsies are usually taken during medical tests (an endoscopy for example) or operations. The biopsy sample is sent to the laboratory and the cells are looked at very closely under the microscope to see if they are normal or cancer cells. NET cells look quite different to normal cells. Doctors can sometimes tell from biopsies where in the body a cancer has started.

Biopsies are very important in medicine. It is virtually impossible to diagnose some types of cancer any other way. Often, the only way to be sure of the diagnosis is to actually look for cancer cells under the microscope.

Blood tests You will be asked to have a fasting gut hormone blood test, and blood will also be collected for a range of other tests.

Doctors will be looking for certain NET markers, particularly chromogranin A and B, and for evidence of a rise in certain peptides and hormones in the blood.

For further information see the NET Patient Foundation Factsheet on Fasting Gut Hormone Profile.

 Other blood tests may include:

  • Full blood count
  • Kidney function test (urea and electrolytes)
  • Liver function tests
  • Thyroid function tests
  • Pituitary hormone screen e.g. adrenocorticotrophic hormone (ACTH), prolactin, growth hormones and cortisol
  • Serum calcium, parathyroid hormone levels (as a simple screening test for MEN-1 syndrome)

Endoscopy This is a way of examining your gastrointestinal tract using a flexible fibre optic tube called an endoscope. The tube can either be inserted down the back of the throat, a procedure called a gastroscopy, or into the colon via the rectum (back passage), a procedure known as a colonoscopy. You will be offered sedation before either of the procedures, and the doctor may remove samples of any suspect areas of tissue for analysis.

Wireless Capsule Endoscopy This involves swallowing a small capsule (the size of a large vitamin pill), which contains a colour camera, battery, light source and transmitter.

Capsule Endoscopy involves swallowing a small (the size of the large vitamin pill) capsule, which contains a colour camera, battery, light source and transmitter. The camera takes two pictures every second for eight hours, transmitting images to a data recorder about the size of a portable CD player that patients wear around the waist.