What is a biopsy?

A biopsy is a procedure in which a doctor removes a sample of abnormal tissue. According to the National Cancer Institute, a pathologist then looks at the tissue under a microscope and runs other tests on the cells, describing the findings in a pathology report that contains details about the diagnosis.

In most cases, doctors need to do a biopsy to be certain that a person has cancer. The information in the report can also help show which treatment options might work.

A biopsy sample may be taken in several ways:

• With a needle, used for bone marrow aspirations, spinal taps, and some breast, prostate, and liver biopsies.
• With endoscopy, where the doctor inserts a thin, lighted tube (an endoscope) into a natural body opening, such as the mouth or anus. Colonoscopy and bronchoscopy are examples.
• With surgery, where a surgeon removes abnormal cells. An excisional biopsy removes the entire abnormal area; an incisional biopsy removes only part of it.

Some biopsies may require a sedative to help you relax, or anesthesia to keep you from feeling pain. A healthcare team can explain which type of biopsy is planned and what to expect.