Stages and types of melanoma

Breslow thickness of melanoma skin cancer

The Breslow thickness describes how deep a melanoma has grown into the layers of skin. Doctors need to know the depth of a melanoma to help stage it.

What is the Breslow thickness of a melanoma?

The Breslow thickness is a measurement of the depth of the melanoma. It is measured from the surface of your skin to the deepest point of the tumour.

Doctors use the Breslow thickness to work out the Tumour (T) stage in the TNM staging system for melanoma skin cancer.

The stage tells you the size of a cancer and if it has spread. Knowing this helps your doctors decide what treatment you need.

Find out more about the TNM staging system

Measuring the Breslow thickness

If your doctor thinks you have a melanoma skin cancer, they remove it to check. This is called an excision biopsy.

A specialist doctor called a pathologist looks at the biopsy in the laboratory to see if it is a melanoma. If it is, they use a special small ruler and a microscope to measure the Breslow thickness. This is measured in millimetres (mm).

Last reviewed: 02 Jan 2025

Next review due: 02 Jan 2028

TNM stages

The TNM stage is a way of describing how thick the melanoma is and if it has spread. TNM stands for Tumour, Node, Metastasis.

Number stages

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.

Treatment for melanoma skin cancer

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 and support

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

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 skin cancer main page

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.