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

What is the Breslow thickness of a melanoma skin cancer?

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.

How does your doctor measure 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).