The Immunology of Melanoma.

The relatively high DNA mutational burden in melanoma allows for the creation of potentially "foreign," immune-stimulating neoantigens, and leads to its exceptional immunogenicity. Brisk tumor-infiltrating lymphocytes, a marker of immune editing, confer improved overall survival in melanoma, possibly due to reduced sentinel lymph node spread. Meanwhile, T-cell-stimulating drugs, so-called T-cell checkpoint inhibitors, which reverse peripheral tolerance-dependent tumor escape, have demonstrated unparalleled clinical success in metastatic melanoma. Markers to predict response to immunotherapy are currently imperfect, and the subject of intense research, which will guide the future of ancillary pathologic testing in this setting.