Tests for skin cancer

If you have an abnormal area of skin that you think might be a cancer, you will need to go to your GP. Your doctor will examine you and listen to what you have to say about it. If your GP thinks you may have a skin cancer, the abnormal area will need to be tested. Your GP will refer you to a team of specialists. The team may be the Local Hospital Skin Cancer Multidisciplinary Team (LSCMDT) or the Specialist Skin Cancer Multidisciplinary Team (SSCMDT). Whichever team your GP refers you to they will have specialist training in skin cancer. Sometimes a referral is needed more urgently. The National Institute for Health and Clinical Excellence (NICE) have produced guidelines for GPs to help them decide which patients need to be seen urgently by a specialist.You can find out more about who you will see in the section about who should see a specialist.

The only way to definitely tell if you have a skin cancer or not is to take a sample of the skin and examine it under a microscope. This is called a biopsy. Usually you have a biopsy under a local anaesthetic. But this will depend on where the possible cancer is and how large it is.

If you have a small skin cancer and your GP surgery has a minor operations unit, you may have the biopsy done there. If not, your GP will refer you to a dermatologist. Dermatologists are doctors who specialise in skin conditions. If the abnormal area is somewhere obvious, such as on your face or hands, your GP may prefer to refer you to a specialist clinic anyway. 

There can be a wait of a few weeks to see a dermatologist. This can be quite unsettling if you are worried that you may have cancer. But non melanoma skin cancer takes years to develop for most people. Waiting a few weeks is unlikely to do any harm. If you are worried about the wait, talk to your GP  ̶̶  particularly if it has taken you a long time to get round to going to see your doctor in the first place. The National Institute for Health and Clinical Excellence (NICE) have produced guidelines for GPs to help them decide which patients need to be seen urgently by a specialist.

When you go to have your biopsy you will have an injection of local anaesthetic into the area to be biopsied. The doctor will then cut out a sample of skin tissue and send it off to the laboratory for examination under a microscope.

There are 3 main types of biopsy and they are

• Incisional or excisional biopsy
• Punch biopsy
• Shave biopsy

Incisional biopsy means using a surgical knife to remove a small piece of the abnormal area. You have a piece of the full thickness of the skin removed. Excisional biopsy is the same, but you have the whole of the abnormal area removed. After these types of biopsies, you need to have some stitches to sew up the area where the skin has been cut out. The stitches stay in for about a week. You may be asked to go back to the clinic to have them removed. If the doctor has used soluble stitches, you won't need to go back to have them removed. These stitches should dissolve on their own.

A punch biopsy means removing a deeper tissue sample. You have a small circle of the full thickness of the skin removed.

A shave biopsy means shaving off the top layer of skin under local anaesthetic.

You may also have a fine needle aspiration (FNA). Or a core needle biopsy which is also called a Tru-Cut biopsy.

You will not get the results of your biopsy straight away. You will get the biopsy result when you go back to see your GP or dermatologist. This is usually about 2 to 3 weeks after the biopsy was done.

If the skin sample contained any cancerous cells, you may have more tests. If the whole abnormal area was removed, it will be closely checked in the lab to make sure a border of healthy skin tissue has been removed around it. This is often called a healthy margin. If any cancer cells are left behind, the cancer can continue to grow and spread into abnormal skin tissue. If your margin is found to have some cancer cells in it you will probably need to have more surgery. This is to make sure that all the suspicious cells have been removed.