Why do I need a biopsy?

In most cases, doctors need to do a biopsy to be certain whether you have cancer. A biopsy is a procedure in which the doctor removes a sample of abnormal tissue.

A pathologist—a doctor with special training—then looks at the tissue under a microscope and runs other tests on the cells. The findings are described in a pathology report, which contains details about your diagnosis and can help show which treatment options might work for you.

A biopsy sample may be taken with a needle, with an endoscope (a thin, lighted tube passed through a natural opening such as the mouth or anus), or during surgery. Some biopsies use a sedative to help you relax or anesthesia so you don't feel pain.

Other tests—such as lab tests and imaging scans—can suggest cancer, but a biopsy is often the only way to know for sure. Your healthcare team is the best source of information about which biopsy you need and why.