- Biopsies - to examine tissue under the microscope. The method and number of biopsies depends on the individual's specific condition and the tissue to be removed. For all biopsies a local anesthetic (lidocaine with or without epinephrine) is injected at the biopsy site. A punch biopsy uses a small sharp cookie-cutter instrument to remove a small (about 1/10- to 1/5-inch) piece of skin. An excisional biopsy uses a small surgical knife or scalpel to remove a piece of tissue, usually requiring some stitches to close the wound.