Neuroendocrine Tumor Tissue Tests

Your doctor may remove a piece of a neuroendocrine tumor to study it in the laboratory. Tumor tissue testing helps identify treatments that are most likely to help treat your cancer.

Procedures for removing tissue samples

A biopsy is for the removal of cells or tissues for testing by a pathologist. The method used to do a biopsy depends on where the tumor is.

Biopsies for gastrointestinal tract

Colonoscopy

Colonoscopy is a procedure to look inside the rectum and colon for abnormal tissue or cancer. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, to be checked under a microscope.

Sigmoidoscopy

Sigmoidoscopy is a procedure to look inside the rectum and sigmoid (lower) colon for polyps, abnormal areas, or cancer. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, to be checked under a microscope.

Endoscopic ultrasound-guided fine needle aspirations (EUS-FNA)

EUS-FNA is a procedure to take a sample of tissue for examination under a microscope. An endoscope is a thin, tube-like instrument that has a light and a lens for viewing with a biopsy needle at the end. An integrated ultrasound probe bounces high-energy sound waves off internal organs and tissues to make a picture on a monitor. This picture helps the doctor see where to place the biopsy needle.

Biopsies for lungs

Fine-needle aspiration (FNA)

Fine-needle aspiration (FNA) is a biopsy of the lung for the removal of tissue or fluid, using a thin needle. A CT scan, ultrasound, or other imaging procedure is used to find abnormal tissue or fluid in the lung. A small incision may be made in the skin where the biopsy needle is inserted into the abnormal tissue or fluid. A sample is removed with the needle and sent to the laboratory. A pathologist then views the sample under a microscope to look for cancer cells. A chest x-ray is done after the procedure to make sure no air is leaking from the lung into the chest.

Laboratory tests for tumor tissue samples

Immunohistochemistry (IHC)

IHC is a test that uses antibodies to check for certain antigens in a sample of tissue. The antibody is usually linked to a radioactive substance or a dye that causes the tissue to light up under a microscope. This type of test may be used to tell the difference between different types of cancer. Typically, pathologists will test tumor tissue for chromogranin A and synaptophysin among other markers.

Ki-67

Ki-67 is a protein that indicates cell division. Pathologists use tumor tissue samples to test for Ki-67 via IHC as well. This test can show how many cells are dividing and how many are resting. The results help to establish a grade for a tumor.