Vitreous histocytology of primary choroidal malignant melanoma.

The cytomorphologic findings of a vitrectomy specimen from the right eye of an 80-year-old woman with an unsuspected primary choroidal malignant melanoma are described. The patient had undergone a closed vitrectomy because of chronic vitreous hemorrhage. Histocytology of the vitreous fluid specimens revealed melanoma cells of variable shape and size (from 30-150 microns) with eccentric nuclei. Many of these cells were binucleated or multinucleated with small, uniform, evenly dispersed intracytoplasmic melanin granules. The histocytologic findings together with the postoperative tumor characteristics by ultrasonography and fluorescein angiography suggested the diagnosis of choroidal malignant melanoma.