A polyp biopsy is a test that takes a sample of, or removes polyps (abnormal growths) for examination.
How the Test is Performed
Some polyps are cancerous (malignant) and the cancer cells are likely to spread. Most polyps are noncancerous (benign). The most common site of polyps that are precancerous and are treated is the colon.
How a polyp biopsy is done depends on the location:
- Colonoscopy or flexible sigmoidoscopy explores the large bowel
- Colposcopy-directed biopsy examines the vagina and cervix
- Esophagogastroduodenoscopy (EGD) or other endoscopy is used for the throat, stomach, and small bowel
- Laryngoscopy is used for the nose and throat
For areas of the body that can be seen or where the polyp can be felt, a numbing medicine is applied to the skin. Then a small piece of the tissue that appears to be abnormal is removed. This tissue is sent to a laboratory. There, it is tested to see if it is cancerous.
How to Prepare for the Test
If the biopsy is in the nose or another surface that is open or can be seen, no special preparation is needed. Your health care provider will tell you if you need to not eat or drink anything (fast) before the biopsy.
More preparation is needed for biopsies inside the body. For example, if you have a biopsy of the stomach, you should not eat anything for several hours before the procedure. If you are having a colonoscopy, a solution to clean your bowels is needed before the procedure.
Follow your provider's preparation instructions exactly.
How the Test will Feel
For polyps on the skin surface, you may feel tugging while the biopsy sample is being taken. After the numbing medicine wears off, the area may be sore for a few days.
Biopsies of polyps inside the body are done during procedures such as EGD or colonoscopy. Usually, you will not feel anything during or after the biopsy.
Why the Test is Performed
The test is done to determine if the growth is cancerous (malignant). The procedure may also be done to relieve symptoms, such as with the removal of nasal polyps.
Examination of the biopsy sample shows the polyp to be benign (not cancerous).
What Abnormal Results Mean
Cancer cells are present. This may be a sign of a cancerous tumor. Further tests may be needed. Often, the polyp may need more treatment. This is to ensure it is completely removed.
- Hole (perforation) in the organ from which the polyp was removed
Biopsy - polyps
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Review Date 1/2/2021
Updated by: Denis Hadjiliadis, MD, MHS, Paul F. Harron, Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.