SKIN BIOPSY

What is skin biopsy?

If your doctor suspects that you have a skin cancer, to confirm it, they will suggest that you have a biopsy.

• Biopsy refers to a procedure where a small sample of the suspicious lesion is removed to have it tested.
• Biopsy sample is then sent to Pathologist to have it examined under microscope to obtain exact diagnosis.

Different types of skin biopsy

• Punch biopsy. Punch biopsy takes a sample or a portion of the lesion (similar manner to hole-puncher). Biopsy wound is allowed to heal on its own.
• Shave biopsy. Takes a larger portion of lesion than punch biopsy. Biopsy wound is allowed to heal on its own.
• Excisional biopsy. Excisional biopsy takes the whole lesion to be tested. This is important if the doctor suspects melanoma. Suturing is required to close the biopsy wound.

Punch biopsy is the commonest form of biopsy and this is a quick and a simple procedure that is performed under local anaesthesia. A small punch of 2-3 mm sample of the lesion is taken for histological examination. This small sample is assumed to represent the whole lesion. Because of this assumption, at times, a portion that has not been biopsied that were assumed to be non-cancerous, are indeed turn out to be cancerous. This is called a sampling error. Therefore, it is imperative that if a lesions is clinically suspicious of being a cancer, it needs to be either re-biopsied or have it monitored. 99% of the wound does not require any stitches but in rare cases a stitch is needed to help the wound to heal and stop the bleeding.

Some lesions such as a potential Melanoma needs a different type of biopsy called excisional biopsy which is also performed under local anaesthesia. This is where a whole lesion is excised for histological examination rather than a small punch. Stitches are usually needed to help the wound to heal. Unlike the less aggressive skin cancers where a small sampling error of punch biopsy can be tolerated, a more aggressive and life threatening melanoma does not share that luxury. We can not take chances in missing a melanoma, as it may prove to be life-threatening.

All tissues that are removed/biopsied are sent to a pathology laboratory to be looked at under a microscope and to get a histological diagnosis. This may take about a week for the results of your tests to be ready, and a follow-up appointment may be arranged for you. This waiting period can be an anxious time and it may help to talk things over with a close friend or relative or your doctor.

Aftercare

Punch or Shave biopsies – wound is left open and not sutured. A pressure dressing is usually applied to prevent bleeding. Pressure dressing can be removed after few hours. There is no special care needed. You can have a shower and get the wound wet.

Excisional biopsy – wound is closed with stitches. A clean dressing is applied. Keep the wound clean and dry for 2 days. From day 3, wound can get wet. Ensure to dry to wound afterwards with clean towel or blow drier. Cleanse the wound twice a day with antiseptic (peroxide solution) and apply moisturiser (Vaseline). If going out, cover the wound with clean dressing. Sutures are usually removed between 5-14 days, depending on the anatomical location and wound healing progress.

CASE STUDIES

Case studies 1-3 on punch biopsy, shave biopsy, and excisional biopsy. click here.