A biopsy is a sample of tissue taken from the body in order to examine it more closely. A doctor should recommend a biopsy when an initial test suggests an area of tissue in the body isn't normal.
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.
Why Are Biopsies Done?
Biopsies are most often done to look for cancer. But biopsies can help identify many other conditions.
A biopsy might be recommended whenever there is an important medical question the biopsy could help answer. Here are just a few examples:
In some cases, a biopsy of normal-appearing tissue may be done. This can help check for cancer spread or rejection of a transplanted organ.
In most cases, a biopsy is done to diagnose a problem or to help determine the best therapy option.
Types of Biopsies
There are many different kinds of biopsies. Nearly all of them involve using a sharp tool to remove a small amount of tissue. If the biopsy will be on the skin or other sensitive area, numbing medicine is applied first.
Here are some types of biopsies:
- Needle biopsy. Most biopsies are needle biopsies, meaning a needle is used to access the suspicious tissue.
- CT-guided biopsy. A person rests in a CT-scanner; the scanner's images help doctors determine the exact position of the needle in the targeted tissue.
- Ultrasound-guided biopsy. An ultrasound scanner helps a doctor direct the needle into the lesion.
- Bone biopsy. A bone biopsy is used to look for cancer of the bones. This may be performed via the CT scan technique or by an orthopedic surgeon.
- Bone marrow biopsy. A large needle is used to enter the pelvis bone to collect bone marrow. This detects blood diseases such as leukemia or lymphoma.
- Liver biopsy. A needle is injected into the liver through the skin on the belly, capturing liver tissue.
- Kidney biopsy. Similar to a liver biopsy, a needle is injected through the skin on the back, into the kidney.
- Aspiration biopsy. A needle withdraws material out of a mass. This simple procedure is also called fine-needle aspiration.
- Prostate biopsy. Multiple needle biopsies are taken at one time from the prostate gland. To reach the prostate, a probe is inserted into the rectum.
- Skin biopsy. A punch biopsy is the main biopsy method. It uses a circular blade to get a cylindrical sample of skin tissue.
- Surgical biopsy. Either open or laparoscopic surgery may be necessary to obtain a biopsy of hard-to-reach tissue. Either a piece of tissue or the whole lump of tissue may be removed.
What to Expect From Your Biopsy
Biopsies vary greatly according to how difficult the tissue is to obtain. The medical term for this is "invasiveness."
A minimally invasive biopsy (for example, most skin biopsies) may be done in the doctor's office during the same visit the lesion is discovered. A small injection of numbing medicine can make the procedure almost painless.
More invasive biopsies may be done in a hospital, a surgery center, or a specialized doctor's office. You would make a separate appointment for the biopsy. In most cases, sedating and pain relief medicines are given, reducing any discomfort. You likely won't be able to drive after receiving these medicines.
You may feel sore at the area of the biopsy for a few days. Your doctor can prescribe appropriate pain relief medicines if you have significant pain from the biopsy.
What Happens After the Biopsy?
After the tissue is collected and preserved, it's delivered to a pathologist. Pathologists are doctors who specialize in diagnosing conditions based on tissue samples and other tests. (In some cases, the doctor collecting the sample can diagnose the condition.)
A pathologist examines the biopsy tissue under a microscope. By noting the tissue cells' type, shape, and internal activity, in most cases a pathologist can diagnose the problem.
The time it takes to get results from a biopsy can vary. During a surgery, a pathologist may read a biopsy and report back to a surgeon in a few minutes. Final, highly accurate conclusions on biopsies often take a week or longer. You will probably follow up with your doctor to discuss the biopsy results.