A biopsy is the removal of tissue from any part of the body in order to examine it for disease. Some biopsies may remove a small tissue sample with a needle while others may surgically remove a suspicious nodule or lump. The type of procedure used to perform a biopsy will depend on the location of the tissue that needs to be examined. Biopsies may be performed using imaging guidance—such as ultrasound, x-ray, computed tomography (CT) or magnetic resonance imaging (MRI)—to determine exactly where to place a needle through the skin to the area of the abnormality.

Doctors may call an area of abnormal tissue a lesion, a tumor, or a mass. These are general words used to emphasize the unknown nature of the tissue. The suspicious area may be noticed during a physical examination or internally on an imaging test.

Biopsies are most often done to look for cancer. But biopsies can help identify many other conditions. A biopsy might be recommended whenever:

• A mammogram shows a lump or mass, indicating the possibility of breast cancer.
• A mole on the skin has changed shape recently and melanoma is possible.
• A person has chronic hepatitis and it’s important to know if cirrhosis is present.