A polyp biopsy is a test that takes a sample of, or removes polyps (abnormal growths) for examination.
Polyps are growths of tissue that may be attached by a stalk-like structure (a pedicle). They are commonly found in organs with many blood vessels, such as the uterus, colon, and nose.
Some polyps are cancerous (malignant) and likely to spread. However, most polyps are noncancerous (benign). The most common site of polyps that are treated is the colon.
How a polyp biopsy is taken depends on the location:
For areas of the body that can be seen, a numbing medication 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, where it is tested to see if it is cancerous.
If the biopsy is in the nose or another surface that is open or can be seen, no special preparation is needed. However, it may be a good idea to fast for a few hours before the biopsy.
More preparation is needed for biopsies inside the body.
For polyps on the skin surface, you may feel a tugging sensation while the biopsy 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 (for example, EGD or colonoscopy). Usually you will not feel anything during or after the biopsy.
The test is done to determine if the growth is cancerous (malignant).
Examination of the biopsy shows the polyp to be benign (not cancer).
Cancer cells are present and may be a sign of a cancerous tumor. Further tests may be needed. Often, the polyp may be removed.
Itzkowitz SH, Potack J. Colonic polyps and polyposis syndromes. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 122.