[Melanocytoma of the iris and ciliary body and multiple pigmented tumors ultrastructural study]

The authors report an ultrastructural study of a melanocytoma of the iris and the ciliary body which has been excised by an iridocyclectomy because of the extension into the angle and of the rapid growth. In this tumor we have found a great number of melanocytes, some melanophages and few collagen fibers. The melanocytes include a lot of mature melanosomes. The melanophages are characterized by the compound melanosomes and the lysosomial bodies. In both cells the number of melanosomes was high, filling nearly all the cytoplasm. The evolution for the eye after the operation was good but the patient died two years later for an unknown reason. This iris tumor was associated with two others pigmented tumors: a benign cystic nevus of the caroncula and a choroidal nevus. The ultrastructural study of the conjunctival nevus shows vacuolated cells under the basement membrane. These cells are organised around large surface of mucus. These epithelial inclusion cells look like pseudocyst formation. The originality of this work is that few melanocytoma of the iris has been studied by transmission electron microscopy and the association with two others benign nevi (caroncula, choroïd).