Ultrastructural Organization of Uveal Melanoma Stromal Cells.

Typical blood capillaries and vessels in uveal melanoma were shown and different types of uveal melanoma stromal cells were determined by electron microscopy and immunohistochemical analysis. Macrophages, fibroblasts of varying degrees of differentiation and endothelial-like cells with numerous caveolae in the cytoplasm were found in the channels of the extracellular matrix surrounding accumulations of tumor cells. The presence local structures positively stained for markers of the blood and lymphatic vessels (CD31 and podoplanin) in channels of the extracellular matrix suggests that the described endothelial-like cells can be the structural basis for blood and lymphatic vessels of the tumor.