Breslowtype

Breslowtype is a nonstandard term that appears in some dermatopathology literature to refer to the Breslow depth or thickness of a malignant melanoma, a concept introduced by Alexander Breslow. While not a formal nomenclature in current guidelines, the idea behind Breslowtype is linked to the measurement of how deeply melanoma cells invade the skin.

Breslow depth is measured in millimeters and is taken from the top of the granular layer of the adjacent epidermis to the deepest point of invasion by tumor cells. If the lesion is ulcerated, the measurement is taken from the base of the ulcer to the deepest invasion. The procedure requires careful examination of representative tumor sections to capture the maximal depth.

In clinical practice, Breslow depth is the principal prognostic factor used in staging cutaneous melanoma and guides treatment decisions. It is integrated into staging systems such as the AJCC classification, which groups tumors by thickness ranges and considers other features such as ulceration and mitotic rate. Modern guidelines emphasize the continuous nature of depth, while older reports often used discrete thickness categories. Clark level, another historical descriptor of invasion, is less prognostically decisive today but may be reported alongside Breslow depth.

Breslowtype, when encountered, is generally understood as a reference to the tumor’s thickness rather than a distinct biological subtype. It is not widely used as a formal term in contemporary pathology reporting. In practice, pathologists report the exact Breslow depth in millimeters and, when relevant, accompanying factors such as ulceration and mitotic rate to inform prognosis and management.

See also: Breslow depth, Clark level, melanoma, melanoma staging.