Spontaneous Necrosis of Choroidal Melanoma.

BACKGROUND/AIMS The purpose of this study was to examine the clinical presentations and pathological features of spontaneously necrotic choroidal melanomas. METHODS The clinical and histological features of patients who underwent enucleation for uveal melanoma from 1989 to 2012 at Emory University and were found to have spontaneously necrotic choroidal melanomas were retrospectively analyzed. RESULTS A total of 6 cases were identified. All cases had 90-100% tumor necrosis and also exhibited marked ischemic necrosis of the iris and ciliary body; 5 of 6 cases exhibited marked ischemic necrosis of the retina. The tumor consisted of melanoma ghost cells often surrounded by a zone of pigmented macrophages. Thrombi were not found in any of the cases. All of the tumors in our cases were centered around the equatorial choroid and 2 extended into the ciliary body. One of the cases exhibited a wedge-shaped infarct in a lateral aspect of the tumor. In most of the cases, microscopic areas of intact tumor cells were present in the peripheries of the tumors. CONCLUSIONS Spontaneous necrosis may occur in uveal melanoma. We believe that this occurs secondary to tumor hypoxia in the center of the tumor, followed by secondary inflammation, generalized ischemia and finally complete tumor necrosis.