If your doctor suspects that a growth on your skin might be skin cancer, you will need a diagnostic test called a biopsy to find out for sure.
A biopsy is a procedure in which the suspicious tissue, or a sample of it, is removed so that it can be examined under a microscope. Usually, skin biopsies are performed in the doctor's office, using local anesthesia. The only discomfort during the procedure comes when the local anesthetic is injected. This stings, just as it does when you have a local anesthetic injected before a dental procedure. Once the anesthetic takes effect, the rest of the procedure should be painless.
Types of Biopsies
Depending on the size, location, and nature of your skin problem, your doctor may perform any one of several different types of biopsies.
In some instances, the doctor may perform an excisional biopsy, in which the entire growth, and sometimes a small area of normal tissue around it, is removed. With an excisional biopsy, a problem can often be diagnosed and cured with a single procedure.
In other instances, the doctor may perform an incisional biopsy or a punch biopsy. In these instances, only a small sample of tissue is removed for testing. If the abnormality turns out to be skin cancer, you will need to return to the doctor's office so that it can be removed completely, along with a small area of the normal tissue around it. If it turns out not to be cancer, you may not need any further treatment.
If an abnormality is present under a fingernail or toenail, the doctor may perform a nail bed biopsy, in which part or all of the nail is removed so that a sample of the suspicious tissue can be taken for examination.
If the doctor suspects that a skin cancer or other problem may have spread to tissues beneath the skin, such as lymph nodes or fat tissue, a needle biopsy may be performed. In this procedure, a small, hollow needle is inserted, usually guided by some form of imaging, such as an x-ray, and a sample of tissue is removed. Needle biopsies are almost never used to diagnose problems in the skin itself.
Regardless of what type of biopsy your doctor performs, you will usually have to wait several days for the report on the microscopic examination of the tissue sample. For most people, this is the hardest part of the whole procedure.
Before You Have a Biopsy
You don't need to do anything special to prepare for a skin biopsy. However, as with any medical procedure, you need to talk with your doctor about the procedure ahead of time. Some of the things your doctor will want to know include the following:
- Whether you are taking any medicines. If you're taking a medicine that affects blood coagulation, such as aspirin or warfarin (Coumadin), that's especially important. It's also important for your doctor to know whether you are taking anti-inflammatory medicines such as prednisone. These medicines change the way your skin tissue looks under a microscope.
- Whether you have any bleeding problems.
- Whether you are allergic to any medicines. It's especially important for your doctor to know if you have ever had a bad reaction to a local anesthetic.
- Whether you are or might be pregnant. You can have a skin biopsy if you are pregnant, but this is still important information for your doctor to have.
After Your Skin Biopsy
Your doctor will tell you how to take care of your biopsy site after the procedure. You will probably be told to keep the site clean and dry until it heals completely. If the doctor put in stitches, you will need to come back to the doctor's office to have them taken out several days after the procedure. If the doctor used adhesive strips, you will probably be told to leave them on until they fall off by themselves, which usually takes one to two weeks.
It is normal for a skin biopsy site to feel sore for several days or to bleed a little. But if you have a great deal of bleeding or if you develop signs of infection (a fever or increased pain, redness, or swelling at the biopsy site), call your doctor. You may need to go back to the doctor's office for further treatment.