[Ultrastructure of leiomyoma of the ciliary body]

Leiomyoma of the ciliary body of the eye was studied with the help of optical microscope at the ultrastructural level. The tumour was characterized by 4 types of cells: micro immature myoblasts, macro differentiated myoblasts, dystrophically changed muscle cells with lipofuscin inclusions, and fibroblasto-like cells. At the luminous level the differentiation of pigmental granules of melanin and lipifuscin was impeded. At the ultrastructural level they had different morphology, and therefore the differential diagnosis of a slightly pigmented melanoma and leiomyoma is possible.