myPath Melanoma measures 23 genes for which expression patterns differ between malignant melanoma and benign nevi. These genes are involved in cell differentiation, cell signaling, and immune response signaling. may be used as an adjunct to histopathology when the distinction between a benign nevus and a malignant melanoma cannot be made confidently by histopathology alone. Reasons that definitive diagnosis may not be achievable by histopathology include indeterminate/ambiguous histopathologic features, diagnostic disagreement among physicians, or indications that additional workup or consultation are necessary. The test measures the expression of 23 genes by qRT-PCR methodology and distinguishes melanoma from nevi with a sensitivity of 90-94% and a specificity of 91-96%. The genes included in myPath Melanoma testing are:
PRAME a single gene involved in cell differentiation
S100A7, S100A8, S100A9, S100A12 and PI3, a group of genes involved in multiple cell signaling pathways
CCL5, CD38, CXCL10, CXCL9, IRF1, LCP2, PTPRC and SELL involved in tumor immune response signaling
Nine housekeeping genes that are measured to normalize RNA expression for analysis