There are four types of biopsy used to diagnose skin cancer: shave biopsy, punch biopsy, incisional biopsy, and excisional biopsy. Dr. Patel, can you tell us more about these procedures?
Definitely, Dr. Mayzik. Prior to any biopsy, the provider will clean and prep the growth and surrounding skin, and mark the area with a skin pen, especially if multiple biopsies are being performed. Each site to be biopsied will be labeled A, B, C, and so on. The provider will numb the area with local anesthetic. In some cases, a photo of the biopsy site may be taken in order to plan future procedures or to document the appearance of the lesion being biopsied.
A shave biopsy can be used to diagnose many types of skin diseases and to sample moles when the risk of melanoma is low.
When a shave biopsy is performed, the provider shaves off the top layers of the skin -- the epidermis and the outer part of the dermis -- with a surgical blade.
A punch biopsy removes a deeper sample of skin. After the skin is numbed with a local anesthetic, the provider uses a tool that looks like a tiny, round cookie cutter. The punch biopsy tool is rotated on the surface of the skin until it cuts through all the layers of the skin and a sample of tissue is removed.
Incisional and excisional biopsies are performed on growths situated in the deeper layers of the skin. An incisional biopsy removes only a portion of the growth. An excisional biopsy removes the growth entirely and is generally the preferred method of biopsy for larger lesions that cannot be adequately assessed with a shave or punch biopsy.
After numbing the area with a local anesthetic, a scalpel or surgical knife is used to cut through the full thickness of skin. A sliver or wedge of skin is taken for examination. Stitches may be needed after these procedures.
Skin biopsy samples are sent to the lab for review by a pathologist, who is specifically trained to examine and diagnose tissue samples.