How is melanoma of the skin diagnosed?

The first sign of melanoma is usually the appearance of a new spot or a change in an existing spot or mole. The change may be in size, shape and/or colour. The change is normally noticed over several weeks or months rather than days.

Most of us have spots on our skin. That’s quite normal, but it’s important to recognise any changes to your spots or moles, including:

A - asymmetry

B - border irregularity

C - colour variation

D - diameter over 6 millimetres 

E - evolving (enlarging, changing).

It is quite normal for new spots or moles to appear and change during childhood and early adulthood, but if you have any concerns, speak with your GP.

"I had a tiny spot on my leg like a freckle. It turned into a lump in a few months and I knew I had to keep going back even though I was told it wasn’t skin cancer (I was overseas at the time). I’m glad I kept pushing to have it retested."

Whai ai te nuinga o tātou i ngā kōiraira ki runga i ō tātou kiri. Kāore he aha mō tēnā, heoi, ko te
mea nui kē, ko te mōhio ki ngā rerekētanga ka puta ki ngā kōiraira, ki ngā ira rānei, tae noa ki

A – te karawhiti

B – te hikuwaru

C – te whitinga kano

D – he weherua nui ake i te 6 tuke haumano.

E – te kukuwha (kei te rahi ake, kei te panoni).

Kāre noa iho he aha mō te putanga ō ētahi kōiraira hou, ira hou rānei, me te panoni i te wā o te tamarikitanga tae noa ki te pakeketanga tōmua, heoi anō, mehemea he āwangawanga ōu, me kōrero ki tō rata.

Melanoma is diagnosed by physical examination and biopsy. Your GP will first examine the spot or mole that you are concerned about and do a general check of your skin. They will ask if you or anyone in your family/whānau have had melanoma.

The best way for your GP to look at your skin is to use a dermatoscope (a handheld magnifying device). Your GP may also feel the lymph nodes in the area near the spot or mole.

IS Dermascope resized

The doctor is checking the skin with a dermatascope

Your GP may also feel for lymph nodes in the area near the spot or mole


Removal of a spot or mole for testing

If your GP is concerned that you may have a melanoma, they will recommend that you have the spot or mole removed for testing. This is usually a quick and simple procedure.

If the mole is in a place that makes it difficult for removal, or if it covers a large area, you will be referred to a specialist skin doctor or plastic surgeon.

It will take at least a week for the results of your test to be ready. This waiting period can be an anxious time and it may help to talk over any concerns with a family/whānau member or close friend.

If the results of any tests show that you have melanoma, you will usually need to have further surgery to remove a wider area of surrounding tissue.

See the Cancer Society’s information sheet Coping with waiting or phone the Cancer Information Helpline 0800 CANCER (226 237).


The stages of melanoma of the skin

Knowing the stage of your melanoma helps your doctor to plan your treatment. Staging is based on the results of your surgery and any other tests you may have had. It describes the thickness of your melanoma, if there is any ulceration, and whether it has spread to other parts of your body.

This table is a simplified version of how melanoma is staged.


This booklet discusses early stage melanoma – stages 0, 1 and 2. For information on stages 3 and 4, see our Advanced Melanoma of the Skin Booklet.


Other tests for melanoma of the skin

If you are diagnosed with melanoma, your doctor may recommend other tests. The tests may include:

• fine-needle aspiration – if you have an enlarged lymph node, your doctor may recommend a
fine-needle aspiration to see if it is due to the spread of melanoma

• sentinel node biopsy – if your melanoma is more than 1mm in thickness (or 0.8mm with ulceration), your surgeon may suggest that you have a sentinel node biopsy at the time of your surgery to see if your melanoma has spread to the lymph nodes closest to your melanoma

• scans –scans may be done if there is a concern that your melanoma has spread to other parts of your body.

• blood tests – to check your general health if surgery is needed.

"In hospital they injected a dye into the melanoma site to see which lymph node the dye went to—a sentinel node biopsy." Karen




 Asking questions about your melanoma diagnosis

When you hear you have melanoma, you and your family/whānau may have many questions. Having your questions answered can help you feel more in control of your situation. It is a good idea to think about some of the questions you might have and write them down before you visit your doctor.

You may want to find out:
• the type of melanoma you have
• if your melanoma has spread and what stage it is
• if you might need other tests.


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