In this section you can find out about the different tests you may need to take to see if you have melanoma.
Waiting for the test results can be a stressful time. It may help to talk to a friend, family member or health professional, or to call Cancer Council 13 11 20.
Learn more about:
- Physical examination
- Removing the mole (excision biopsy)
- Checking the lymph nodes
- Pathology report
- Video: Cancer and common diagnostic tests
If you notice any changes to your skin, your doctor will examine you, looking carefully at any spots you have identified as changed or suspicious. The doctor will ask if you or your family have a history of melanoma. Using a handheld magnifying instrument called a dermoscope, the doctor will examine the spot more closely and consider the criteria known as “ABCDE”.
ABCDE signs of melanoma
|Asymmetry||Are the halves of each mole different?|
|Border||Are the edges uneven, scalloped or notched?|
|Colour||Are there differing shades and colour patches?|
|Diameter||Is the spot greater than 6 mm across?|
|Evolving||Has the spot changed over time (size, shape, surface, colour, bleeding, itching)?|
Some types of melanoma, such as nodular and desmoplastic melanomas, don’t fit the “ABCDE” criteria, so your doctor may also assess whether the spot is elevated, firm or growing.
If the doctor suspects that a spot on your skin may be melanoma, the whole spot is removed (excision biopsy) for examination by a tissue specialist (pathologist). This is generally a simple procedure done in your doctor’s office. Your GP may do it, or you may be referred to a dermatologist or surgeon.
For this procedure, you will have an injection of local anaesthetic to numb the area. The doctor will use a scalpel to remove the spot and a small amount (2 mm margin) of healthy tissue around it. The wound will usually be closed with stitches. It is recommended that the entire mole is removed rather than a small sample. This helps ensure an accurate diagnosis and accurate staging of any melanoma found.
A pathologist will examine the tissue under a microscope to work out if it contains melanoma cells. Results are usually ready within a week.
For information about what the pathology results mean, see below.
You’ll have a follow-up appointment to check the wound and remove the stitches. If a diagnosis of melanoma is confirmed, you will probably need further surgery, such as a wide local excision.
Lymph nodes are part of your body’s lymphatic system, which removes excess fluid from tissues, absorbs fatty acids, transports fat, and produces immune cells. There are large groups of lymph nodes in the neck, armpits and groin. Sometimes melanoma can travel through the lymph vessels to other parts of the body.
Your doctor may feel the lymph nodes near the melanoma to see if they are enlarged. To test whether the melanoma has spread, your doctor may recommend that you have a fine needle biopsy or a sentinel lymph node biopsy.
Fine needle biopsy
A thin needle is used to take a sample of cells from an enlarged lymph node. Sometimes an ultrasound helps guide the needle into place. The sample is then examined under a microscope to see if it contains cancer cells.
If the Breslow thickness of the melanoma is over 1 mm or sometimes for people with melanoma between 0.8 mm to 1 mm, you may be offered a sentinel lymph node biopsy. This biopsy finds and removes the first lymph node/s that the melanoma would be likely to spread to (the sentinel node/s). It is usually done at the same time as the wide local excision.
A sentinel lymph node biopsy can provide information that helps predict the risk of melanoma spreading to other parts of the body. This information can help your doctor plan your treatment. It may also allow you to access new clinical trials.
To find the sentinel node/s, a small amount of radioactive dye is injected into the area where the melanoma was found. The surgeon removes the node that absorbs the injected fluid to check for cancer cells. If they are found in the sentinel lymph node, further tests such as ultrasound, CT or PET scans may be done during follow-up and systemic treatment may be offered.
If you have melanoma, the report from the pathologist will provide your treatment team with information to help determine the stage, plan treatment, and work out your prognosis. You can ask your doctor for a copy of the results, and discuss the results with them. The following factors may be included:
This is a measure of the thickness of the tumour in millimetres to its deepest point in the skin. The thicker a melanoma, the more likely it could return (recur) or spread to other parts of the body.
Melanomas are classified as:
- in situ – found only in the outer layer of the skin
- thin – less than 1 mm
- intermediate – 1–4 mm
- thick – greater than 4 mm.
The breakdown or loss of the outer layer of skin over the tumour is a sign of rapid tumour growth.
Mitosis is the process by which one cell divides into two. The pathologist counts the number of actively dividing cells to calculate how quickly the melanoma cells are dividing.
This describes how many layers of skin the tumour has gone through. It is rated I–V, with I the shallowest and V the deepest. Breslow thickness is much more important than Clark level in assigning a stage to a melanoma.
This is the area of normal skin around the melanoma. If there is no tumour touching the margins, the pathologist will often describe how close the abnormal tissue (lesion) was from the edge.
The report will note any lymphocytes (immune cells) within the melanoma and any evidence of whether some melanoma cells have been destroyed by the immune system and replaced with scar tissue.
Video: Cancer and common diagnostic tests
A/Prof Victoria Atkinson, Senior Staff Specialist, Princess Alexandra Hospital, Visiting Medical Oncologist, Greenslopes Private Hospital, and The University of Queensland Clinical School of Medicine, QLD; Adjunct Prof John Kelly AM, Consultant Dermatologist, Victorian Melanoma Service, and Department of Medicine at Alfred Health, Monash University, VIC; Dr Alex Chamberlain, Dermatologist, Glenferrie Dermatology, Victorian Melanoma Service and Monash Univeristy, VIC; Alison Button-Sloan, Melanoma Patients Australia; Peter Cagney, Consumer; Prof Brendon J Coventry, Associate Professor of Surgery, The University of Adelaide, Surgical Oncologist, Royal Adelaide Hospital, and Research Director, Australian Melanoma Research Foundation, SA; Dr David Gyorki, Consultant Surgical Oncologist, Peter MacCallum Cancer Centre, VIC; Liz King, Skin Cancer Prevention Manager, Cancer Council NSW; Shannon Jones, SunSmart Health Professionals Coordinator, Cancer Council Victoria; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council WA; Prof Richard Scolyer, Senior Staff Specialist, Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Co-Medical Director, Melanoma Institute Australia and Clinical Professor, The University of Sydney, NSW; Heather Walker, Chair, Cancer Council National Skin Cancer Committee, Cancer Council Australia. We also thank the health professionals, consumers and editorial teams who have worked on previous editions of this title.
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The information on this page is also available for download.
Patient rights and responsibilities
What you can reasonably expect from your health care providers
Learn more about skin cancer, which is the uncontrolled growth of abnormal cells in the skin
Dealing with the diagnosis
Common reactions to a cancer diagnosis and how to find hope