Equipment needed for a punch biopsy includes Q-tips, pick-ups, scissors, needle drivers, suture, tissue punch, gauze, alcohol swab, surgical marking pen, and appropriate wound cover. The area is draped, cleansed, and prepped with an alcohol swab. A surgical marking pen is then used to mark the lesion. The area is then anesthetized with 1% lidocaine with epinephrine, buffered with sodium bicarbonate. The area is injected with subcutaneous, followed by intradermal injections. Anesthesia is confirmed with probing the area to be biopsied with the tip of the needle. Stabilize the skin with the thumb and forefinger, stretching it slightly perpendicular to the normal skin tension lines. This will produce an oval rather than a round wound, facilitating closure. Place punch perpendicular to the skin and apply firm and constant downward pressure with a circular twisting motion. It is very important to handle the tissue gently at this point to avoid crush artifact. Crush artifact is the distortion of the tissue prior to histopathologic analysis, which can impair the rendering of an accurate diagnosis. Once you reach the subcutaneous fat, you will feel a give, which indicates that a full thickness cut has been made. Remove the punch biopsy and apply downward finger pressure at the size of the wound to pop up the core. Completely elevate the core with a gentle use of forceps or a needle tip and excise it at the base with small tissue scissors. Apply pressure to the wound with gauze in preparation for closure. Hemostasis can be achieved with pressure, gel foam plagettes, Monsel solution, or aluminum chloride. In this example, hemostasis was achieved through the use of a nylon suture. Of note, biopsy sites can heal by secondary intention, but those greater than 3mm may produce unacceptable scarring and are best closed with one or two nylon interrupted sutures. Contraindications to suturing include biopsies in infected or poorly healing skin.

punch biopsy

equipment

Q-tips

lidocaine with epinephrine

hemostasis