A skin biopsy is an important tool for the investigation and management of skin conditions.
It involves taking a small piece of skin from a suspicious area sending it to a laboratory. There, a pathologist will examine all layers of your skin under a microscope, and provide the result within about a week. Biopsy results can either reassure you that the spot in question is non-cancerous (benign) or let you know if it’s cancer, so you can get started on treatment.
A skin biopsy may be necessary to diagnose or to help treat skin conditions and diseases, including skin cancers (basal cell carcinoma, squamous cell carcinoma, and melanoma), actinic keratosis, blistering skin disorders, skin infection, suspicious moles, warts, and other growths.* It is also used to help work out the cause of some rashes on the body or genitals, and even to investigate the cause of hair loss.
The choice of different skin biopsies is dependent on the suspected diagnosis of skin lesion. Four main types of skin biopsies are:*
- Shave biopsy – This can be used to remove squamous cell or basal cell cancers that are sections of the top layers of skin (a portion of the dermis and epidermis). The doctor will use a scalpel, razor, blade, or other surgical tools to shave. Stitches are usually not necessary after this procedure.
- Punch biopsy – This technique uses a small circular blade that can push down to the deeper layers of skin (epidermis, dermis, and superficial fat) and is rotated to remove the skin. Once the specimen has been obtained, small stitches will be used to close the wound, and pressure is applied to the area until bleeding stops.
- Incisional and excisional biopsies – These techniques both use a surgical knife (scalpel) to remove tumors that are deeper in the skin, and both need stitches to close the wound. The difference is excisional biopsy will cut out the entire area of abnormal skin, including a portion of healthy tissue down to the fatty layer of skin, while an incisional biopsy will take a smaller section of tissue.
- Your skin will first be cleaned and then the biopsy area will be outlined with a surgical marker or marking pen.
- You will receive an anaesthetic (pain-relieving) injection through a needle to numb the skin, so you won’t feel any pain during the procedure.
- The skin is then sampled using one of the above biopsy techniques.
- Shave biopsies do not usually need stitches, while punch, incisional and excisional biopsies will need stitches for wound closure.
- The sample will be sent to a laboratory for further examination.
You don’t need any special preparations for a skin biopsy, but you may like to have an arranged driver on the day.
We use a checklist to identify any special circumstances prior to performing your skin biopsy. We will ask you about:
- Your medical history, such as skin infections and bleeding disorders.
- Medications you are taking, including blood-thinners, herbal remedies and immune-suppressant drugs.
- Please inform us if you think you may be pregnant or if you are breastfeeding.
You may be asked to sign a consent form that says you understand the risks of the biopsy and agree to have it done.
Normally, the wound may cause slight pain, itching, bleeding, bruising, and a small scar. However, if you have problems with wound healing such as keloids (overgrown scars), infection, continuous bleeding, or allergic reaction please contact the doctor.
- You will be provided with a take-home handout on how to care for your biopsy site.
- We will also go through this with you before you leave, so that you can ask any questions.
- Generally, the area must be kept covered and dry for 72 hours after your biopsy.