[Mast cells in the microenvironment of uveal melanoma]

To study the morphological features of the microenvironment of a tumor nodule in the eyes with uveal melanoma, focusing on mast cells.

A total of 43 enucleated eyes with uveal melanoma (260 histological specimens) were examined. The patients' age averaged 54±2.7 years. The morphopathological types of tumors were as follows: epithelioid-cell (n=9; 20.9%), spindle-cell type AB (n=15; 34.9%), and mixed-cell (n=19; 44.2%). The tumor prominence was 4.7±1.3 mm; the base diameter was 13.5±3.3 mm. Statistical methods, such as Microsoft Excel, Statistica 10.1, Spearman's rank correlation coefficient (rs), were applied.

Mast cells in the microenvironment of uveal melanoma were present in 18 (41.9%) of the 43 eyes. There was a significantly higher correlation between the mixed-cell type of tumor and the accumulation of mast cells (r_s=0.636). The correlation coefficient (rs) of the number of mast cells with the degree of tumor pigmentation in terms of densely and weakly pigmented forms was 0.571 and 0.717, respectively. Tumor invasion through the sclera was detected in 7 (16.3%) eyes with mast cells (r_s=0.395). Tumor growth in the emissarium in the presence of mast cells was determined in 8 (18.6%) cases (r_s=0.469). Comparison established a correlation between the number of mast cells and the sections of tumor blood vessels (r_s=0.21). Granulated cells were noted in 15 (34.9%) cases; degranulated ones were seen in 3 (7%) cases of the 43 examined eyes. with an ejection of granules around the tumor cells, which may be evidence of their interaction. Granules were ascertained to be released around the tumor cells, which may be suggestive of their interaction.

The study of the mast cell population as one of the components of the tumor microenvironment can be used to elaborate novel approaches for the targeted treatment of uveal melanoma, in particular for its impact on tumor angiogenesis, by using mast cell inhibitors. Therefore, it is relevant and promising to conduct further investigation of mast cells in uveal melanoma.