Skin Cancer Melanoma Biopsy Report | Dermatology Education Skin Cancer Melanoma Biopsy Report Video
November 27, 2021

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Skin Cancer Melanoma Biopsy Report

The biopsy report should state the diagnosis, anatomic site, Breslow level, and whether biopsy margins are involved. Tumor thickness, as defined by the Breslow depth, is the most important histologic determinant of prognosis. The tumor is step sectioned. The section with the deepest level of penetration of tumor is used to measure thickness. An ocular micrometer is placed on the microscope. The pathologist measures the thickness of the tumor in millimeters from the top of the granular cell layer (or base of superficial ulceration) to the deepest part of the tumor. The report is given as Breslow level, followed by the depth reported in millimeters. The presence of ulceration microscopically, defined as the loss of epidermis overlying the melanoma, is the next most important histologic determinant of patient prognosis and should be used to upstage patients with melanoma when present. Ulceration or regression, if present, raises the possibility that the Breslow level may be underestimated. Clark’s levels measure tumor invasion anatomically. The tumor depth is reported by anatomic site (i.e., epidermis, depth in dermis, etc.) and assigned a Clark level of invasion. Clark levels appear to affect prognosis only in thinner (