Choroidal melanoma with retinal perforation and vitreous hemorrhage: a scanning electron microscopic study.

Extensive retinal perforation and subsequent growth within the vitreous cavity permitted the scanning electron microscopic examination of a primary, mixed cell type malignant melanoma of the choroid. The surface of the tumor was covered by fusiform cells oriented in a longitudinal, parallel fashion. Plumper globoid, presumed epitheloid forms were interspersed among the spindle cells. In some areas, the spindle cells had long tapering processes. At the margin of the tumor, slender fascicles of parallelly oriented, proliferating spindle cells were identified. This fascicular growth pattern has been observed in previous tissue culture and scanning electron microscopic studies. Vitreous hemorrhage which occurred in our case may herald a malignant melanoma that has perforated the retina. Additionally, retinal perforation may signify an aggressively growing tumor which should be treated.