A skin lesion biopsy is a simple medical procedure in which a sample of your skin is removed and tested in a laboratory.
The sample taken during a biopsy is often very small, sometimes the size of a grain of rice. The sample size is just large enough for laboratory technicians to test for various issues that could be the cause of a skin lesion. However, the biopsy sample may be larger if the entire lesion is removed.
There are several ways your doctor can collect a skin sample. The procedure your doctor chooses will depend on your individual circumstances.
A doctor who specializes in skin (dermatologist) is typically the doctor who performs a skin biopsy. It’s an outpatient procedure, which means you won’t have to be admitted to a hospital.
A skin biopsy is performed to help determine the cause of a growth, sore, or rash. This could include:
- changing moles
- chronic bacterial or fungal skin infection
- noncancerous growths
- precancerous cells
- skin cancer
- rashes or blistering skin conditions
Any medical procedure that involves breaking the skin involves the risks of bleeding and infection. If you have a history of bleeding problems, you should inform your doctor.
There is also a risk of scarring. If your doctor uses an excisional biopsy, you will have a small scar after the procedure. Other biopsy types rarely leave noticeable scars.
A skin lesion biopsy requires little preparation from you. If you’re having a biopsy done on an open wound or infected patch of skin, your doctor will have to remove any bandaging.
There are several ways your doctor may remove a sample of tissue. The method your doctor chooses for you will depend on the reason for the biopsy location, size, and type of your lesion or sore.
Before any type of biopsy, you’ll receive local anesthesia to numb the biopsy site. Possible methods of collecting a skin sample for biopsy include the following.
- Shave biopsy: Your doctor will remove only the outermost layers of your skin with a special razor blade or scalpel.
- Punch biopsy: This uses a small, tube-like instrument with a sharp end that works like a cookie cutter. Once the right sample is taken, your doctor will remove the skin sample with tweezers and close the incision with a single stitch.
- Excisional biopsy: This is used to remove the entire lesion. Your doctor makes an incision and, going as deeply as necessary, removes the entire lesion. Several stitches are used to close the wound.
- Incisional biopsy: This is used to remove a small part of a larger lesion. The procedure is the same as with the excisional biopsy.
If your doctor suspects that a growth is caused by the most aggressive form of skin cancer (melanoma), they will use an excisional biopsy to remove any potentially cancerous tissue along with a small border of healthy skin. The sample will then be sent to the lab for testing.
After the biopsy, the wound will be covered with gauze and other bandaging. You’ll be able to go home once the sample has been taken.
After the tissue sample is taken, it’s sent to a laboratory for testing. It usually takes about one week for the results to come back, but some tests can take longer. If it’s an emergency situation, like an aggressive infection or cancer, your doctor may put a rush on the results.
When the results of your tests are back, your doctor may discuss them with you over the phone or call you into their office for a follow-up appointment to share the results.
If your results show signs of cancer or other problems, your doctor will discuss the next course of action. This may include other tests or treatments.