Immunophenotypic Differences in Tumor-Infiltrating Lymphocytes and Neovascularization Between Primary Cutaneous Melanoma With and Without Metastasis: An Immunohistochemical Study of 80 Cases

The prognostic implications of the immunophenotype of the tumor-infiltrating lymphocytes (TILs) in primary cutaneous melanoma are well known. In recent years, the study of this immunophenotype has also resulted in immunotherapeutic consequences. The aims of this study were to characterize the subpopulations of TILs in primary cutaneous melanoma, in cases with and without metastasis, as well as the neovascularization associated with the primary neoplasm, and its influence on the development of metastasis. To this end, the immunophenotype of TILs and the neovascularization of 80 patients with primary cutaneous melanoma (40 each with metastatic and non-metastatic melanoma) were analyzed by immunohistochemistry for CD3, CD4, CD8, FOXP3, PD-1, CD31, and D2-40 antibodies. We found that higher frequencies of TILs with brisk pattern, and CD4(+), CD8(+), and CD20(+) cells in TILs, and a lower frequency of CD31(+) vessels were histopathological features associated with better prognosis in primary cutaneous melanoma. Our results support the notion that the immunohistochemical study of TILs and neovascularization in primary cutaneous melanoma may be helpful tools for identifying patients at increased risk of metastasis development.