Histological examinations of 508 uveal melanoblastomas revealed morphological features of cell-mediated immune response and signs of degeneration and necrosis in a large number of tumors. Both histochemical and ultrastructural studies indicated a high functional activity of lymphocytes, plasma cells, and macrophages infiltrating the tumors. The intensity of lymphocyte-plasma cell infiltration of melanoblastomas was found to depend on the cell type of the tumor, its size, and relation to the surrounding tissues. The results of the study suggest that spindle-cell type A melanoblastomas are the least immunogenic and mixed and epithelioid melanoblastomas are the most immunogenic. It has first been shown that the presence of lymphocyte-plasma cell infiltration in spindle-cell type B, mixed, and epithelioid melanoblastomas is an unfavourable prognostic sign.
Humans Lymphocytes