Characterization of cellular infiltration in choroidal melanoma

An immunohistochemical double staining technique was used to examine the characteristics of cellular infiltration in choroidal melanoma. Seven of 16 melanomas examined demonstrated high levels of cellular infiltration, mainly with T-cells and macrophages, and little infiltration with B-cells and NK cells. The majority of T-cells were of the CD8+ type and were activated, as shown by the expression of histocompatibility antigens, HLA-DR and IL2-R. Most of the infiltrating macrophages also expressed HLA-DR antigen. We also detected malignant melanocytes expressing the HLA-DR antigen. This technique could be used to study in detail cellular infiltration in a large number of archival choroidal melanomas with known clinical history, which would enable detection of markers that correlate with the prognosis of the disease.