How Your Doctor Uses Biopsies to Diagnose Skin Cancer
The only way to confirm that a suspicious place on the skin, called a lesion, is cancer is to do a biopsy. Melanoma biopsies are almost always done in a doctor’s office or hospital. Your doctor can take a biopsy in several ways. For any type of biopsy, your doctor numbs your skin with a local anesthetic before removing the tissue. You may feel a little needle stick, burning, or pressure for less than a minute. You will be awake, but shouldn’t feel anything. Which technique your doctor uses depends on the size and location of the lesion. These are the different ways of doing a skin biopsy:
Excisional biopsy. The doctor uses a sharp knife called a scalpel to remove the whole lesion. The doctor also removes some surrounding normal tissue. This is the preferred method for removing a tissue sample to check for melanoma if it can be done.
Incisional biopsy. Sometimes lesions on areas of the body such as the face require more delicate surgery. In these cases, the surgeon may do an incisional biopsy. The doctor uses a scalpel to remove just part of the lesion.
Punch biopsy. Doctors use this procedure when the lesion is small or when just a part of a larger lesion needs further study. This technique uses a punch scalpel, which looks like a small tube with a very sharp edge. Your doctor twists the sharp edge against the skin and uses scissors to divide the attachment at the base.
Shave biopsy. In this technique, the doctor raises the lesion from the skin with a pair of forceps. Then, the doctor uses a scalpel to shave off the top layers of skin. Sometimes part of the lesion may be left behind. You may need another procedure to remove it completely. This type of biopsy is not usually recommended for melanoma because it often does not allow the doctor to tell the exact thickness of the melanoma.
Once your doctor has a tissue sample, he or she sends it to a specialist, called a pathologist, who looks for abnormal cells under a microscope. It usually takes several days for the results of your biopsy to come back.