[The ultramicroscopic aspects in malignant choroidal melanoma]

The survey focuses on the observation using the electronic microscope of two cases of uveal malignant melanoma. The ultrastructure of the cellular population which from this type of malignant tumour was followed, mentioning both the common and the particular aspects. The nuclear and nucleolar modifications, indicating an increase degree of atypia for the epithelioid cells compared with the fusiform cells, were observed. Some aspects of the abnormal tumoural cells were also emphasized. We noticed in the structure of the tumours, besides the tumoural cells, another structure of non-tumoural macrophage and reticular cells, and we described their ultrastructure.