Stages and types of melanoma
The number stage of a melanoma tells you how thick it is and if it has spread. It also tells you whether the top layer of the melanoma looks broken (ulcerated) when looked at under a microscope. Knowing this helps your doctor decide which treatment you need.
Doctors also use another staging system for melanoma called the TNM staging system. It stands for Tumour, Node, Metastasis.
T describes the size of the tumour
N describes whether there are any cancer cells in the lymph nodes
M describes whether the cancer has spread to a different part of the body
The TNM staging system describes the cancer in detail. The number staging system puts these details together to give an overall stage. This can be easier to understand.
In the TNM staging system, stage 3 is:
Any T, N1 to N3, M0
Find out more about TNM staging for melanoma skin cancer
To diagnose melanoma your doctor removes the abnormal area and a small area of surrounding skin. This is called an excision biopsy. A specialist doctor (pathologist) looks at the biopsy under a microscope. If there are melanoma cells, they will work out the stage of the cancer.
You normally have some other tests and scans to help with this.
Read more about the tests for melanoma skin cancer
Stage 3 generally means that cancer cells have spread to either:
an area between the melanoma and the nearby
the lymph nodes close to where the melanoma started
Sometimes doctors find melanoma cells in the lymph nodes or nearby but can’t find the original (primary) melanoma.
Cancer cells found between the melanoma and the nearby lymph nodes are called either:
This this when tiny amounts of cancer cells found next to the melanoma. These can only be seen through a microscope.
These are cancer cells found within 2cm of the melanoma.
These are cancer cells that have spread more than 2cm away from the melanoma but not as far as the nearest lymph node.
Stage 3 melanoma can be divided into A, B, C and D depending on if there are:
micro satellite, satellite or in-transit metastases
cancer cells in one or more lymph nodes
Your doctor or specialist nurse can tell you what your exact stage of melanoma is and what it means.
The lymph nodes are part of the lymphatic system. This is a network of thin tubes (vessels) and small pieces of tissue (nodes) that carry a fluid called lymph around the body. The lymphatic system is an important part of the . It plays a role in fighting infection and destroying old or abnormal cells.
Lymph nodes are bean shaped. They filter the lymph fluid and trap bacteria, viruses and cancer cells.
Read more about the lymph nodes and cancer
Your doctor will usually recommend a test to see if there are cancer cells in the lymph nodes near the melanoma.
You normally have a test called a sentinel lymph node biopsy (SLNB). Your doctor removes the first lymph node or nodes that the melanoma could have spread to.
You have a SLNB at the same time as a .
Read more about having a sentinel lymph node biopsy
If your doctor can feel that your lymph nodes near the melanoma are swollen (enlarged), you usually have an ultrasound scan instead of an SLNB. They may take a sample of tissue (biopsy) from the lymph node to check for cancer cells.
Read more about having an ultrasound and lymph node biopsy
The stage of the cancer helps your doctor decide what treatment you need. Treatment also depends on:
where the melanoma is
your general health and level of fitness
Surgery is the main treatment for stage 3 melanoma. In Scotland, some people may be able to have before surgery. Doctors call this .
Your doctor will send a sample of the melanoma for genetic testing. This is to look for changes to a called the BRAF gene. These gene changes can make melanoma cells grow.
If you have changes in the BRAF gene, doctors describe the melanoma as BRAF positive. If you don’t have changes, then the melanoma is BRAF negative. This is also called BRAF wildtype. Knowing this helps your doctor decide whether you should have immunotherapy or targeted cancer drugs.
Your doctor will normally remove the melanoma in an operation called a wide local excision. They may also be able to remove some micro satellite, satellite or in-transit metastases.
If you can’t have surgery, or you have had metastases treated before and they’ve come back, you might have one of the following:
an injection of treatment directly into the melanoma (intralesional therapy), for example talimogene laherparepvec (T-VEC)
combined with an electric current (electrochemotherapy)
chemotherapy directly into the leg or arm where the melanoma is - isolated limb infusion or isolated limb perfusion
immunotherapy
chemotherapy into your bloodstream (intravenously)
imiquimod cream
Find out about the different treatments for melanoma skin cancer
If your lymph nodes feel normal, but an SLNB shows a small number of melanoma cells have spread there, you might have:
treatment with targeted cancer drugs or immunotherapy
regular scans to check your lymph nodes
You don’t usually have surgery to remove the rest of the lymph nodes in this situation. Your doctor will talk to you about this.
You usually have surgery to remove the lymph nodes in the area. You may also have the lymph nodes removed if they look abnormal and a biopsy shows they have cancer cells in them.
This operation is called a completion lymph node dissection.
Read more about surgery to remove the lymph nodes
After surgery to remove the lymph nodes your doctor might offer you targeted or immunotherapy drugs. The aim is to reduce the chance of the cancer coming back. This is called adjuvant treatment.
You might have targeted cancer drugs or immunotherapy for a year.
Find out about targeted cancer drugs and immunotherapy
Your doctor might ask if you’d like to take part in a clinical trial. Doctors and researchers do trials to make existing treatments better and develop new treatments.
Find out more about clinical trials
Last reviewed: 03 Jan 2025
Next review due: 03 Jan 2028
If you have symptoms of melanoma skin cancer you should see your GP. They might ask you to have some tests and may refer you to a specialist.
The stage of a melanoma skin cancer tells you how deeply it has grown down into the skin. It also tells you if it has spread elsewhere in your body and how far.
Treatments include surgery, cancer drugs and sometimes radiotherapy. Which ones you have depends on the melanoma stage, where on your body it is and your general health.
Coping with melanoma skin cancer can be difficult. You might find it helpful to talk about your feelings. And there are people who can support you and your family.
Survival for melanoma skin cancer depends on many factors including the stage of the cancer when it was diagnosed, the treatment you have and your general health.
Melanoma develops in cells called melanocytes. You have these in your skin and other parts of your body. Melanoma that starts in the skin is called melanoma skin cancer.
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