01What is a skin biopsy?
A biopsy removes a small piece of skin, or a whole spot, so it can be examined under a microscope by a pathologist. It is the only way to know for certain what a spot is.
Biopsies are commonly used to check moles, scaly patches, sores that do not heal and lumps under the skin.
02Types of biopsy
A punch biopsy uses a small circular blade, usually 3 to 6 mm, to take a core of skin; one or two stitches may be needed. A shave biopsy removes a raised spot level with the skin and usually heals without stitches.
An excisional biopsy removes the whole spot with a small margin of normal skin and is closed with stitches. An incisional biopsy removes part of a larger area. Your GP will explain which suits your spot and why.
03Minor excisions
A minor excision removes a skin cancer, cyst, lipoma or other lesion completely. The wound is usually shaped as a thin ellipse so it closes neatly in a straight line.
Lesions on the face, near the eyes or lips, or that are large or deep may be referred to a dermatologist or plastic surgeon.
04Preparing for your procedure
Tell your GP about blood thinners, aspirin, fish oil and supplements, allergies to local anaesthetic, dressings or tape, and any history of poor healing or keloid scars. Do not stop prescribed medicines unless your doctor advises.
Eat normally, wear comfortable clothing that gives easy access to the area, and plan to avoid heavy exercise for a few days if the area is under tension.
05On the day
Your GP confirms the spot, cleans the skin and injects local anaesthetic, which stings for a few seconds and then numbs the area. You will feel pressure but should not feel sharp pain.
The procedure usually takes 15 to 30 minutes, including stitching and dressing. You can usually drive home and return to most normal activities the same day.
06Risks and side effects
All procedures leave a scar, which usually fades over months. Other possible risks include bleeding, bruising, infection, the wound opening, numbness and, rarely, a raised or thickened scar.
Your GP will explain the risks for your site and how to reduce them.
07Aftercare and stitch removal
Keep the dressing on and dry for 24 to 48 hours, then follow your wound care instructions. Avoid stretching the area, swimming and heavy lifting until the stitches are out.
Stitches are usually removed after about 5 to 7 days on the face, 7 to 10 days on the body and 10 to 14 days on the legs, back or feet.
08Results
The sample is sent to pathology, and results usually take a few days to a week. Book a follow-up appointment to discuss them.
If the result shows a skin cancer, your GP will explain whether the margins are clear and whether further treatment or a specialist referral is needed.