How Your Doctor Uses Biopsies to Diagnose Skin Cancer
Nonmelanoma Skin Cancer: Diagnosis
Diagnosing skin cancer starts with checking out a bump, spot, or other mark on your skin. Any area of skin that doesn’t look normal and may have disease is called a lesion. You may have a biopsy of the lesion.
Make sure to tell your health care provider if you’ve had skin cancer in the past. Also note whether anyone in your family has had skin cancer.
Getting a biopsy
A biopsy is a sample of tissue that’s taken to be checked in a lab. Your health care provider will likely take a biopsy of any lesion that may look like cancer.
Types of biopsies
The different types of biopsies include the following:
Excisional biopsy. This type of biopsy is often used when a wider or deeper piece of the skin is needed. The entire lesion and part of the surrounding skin is removed. First, a local anesthetic is used to numb the area. Using a surgical knife (scalpel), a full thickness wedge of skin is removed. The wound is closed with surgical thread (sutures), staples, steri-strips, or surgical glue. This depends on the size and location of the incision.
Incisional biopsy. This procedure is the same as an excisional biopsy. However, only part of the lesion is removed.
Punch biopsy. This type uses a special tool to take a deep sample of skin. This may be done if the lesion is small or when just a part of a larger lesion needs further study. The tool removes a short cylinder of tissue, like an apple core. First, a local anesthetic is used to numb the area. The punch tool is turned on the surface of the skin until it cuts through all the layers of skin. This includes the dermis, epidermis, and the most superficial parts of the subcutis (fat). The biopsy sample is removed and the edges of the wound are then stitched together.
Shave biopsy. This type of biopsy removes the top layers of skin of a lesion. The layers are shaved off with a scalpel. Shave biopsies are done with a local anesthetic. Sometimes part of the lesion may be left behind. You may need another procedure to remove it completely, if needed.
Lab tests of your biopsy sample
A biopsy sample is sent to a lab, where a doctor called a pathologist looks at them under a microscope.
If skin cancer is found, the pathologist will look at certain features of the lesion. These include the thickness of the lesion. This can help determine the extent (stage) of the skin cancer. The stage of skin cancer helps determine treatment options.
Getting your biopsy results
Your biopsy results will likely be ready in a few days to a week or so. Your health care provider will notify you of the results. He or she will talk with you about other tests that may be needed if skin cancer is found.