FAQs: What is ‘Breslow thickness’ in melanoma?

First described by pathologist Alexander Breslow in 1970, ‘Breslow thickness’ is a measurement of the depth of invasion of melanoma into the skin tissue, and remains the most reliable indicator of disease prognosis. The Breslow thickness is defined as the maximum vertical depth, in millimetres, of melanoma cancer cell infiltration below the granular cell layer, which is the most superficial layer of living skin cells in the epidermis. It is measured from excisional biopsies in the laboratory using an ocular micrometer.