Cavitary melanoma of the ciliary body. A study of eight cases.

Abstract

The authors present the unique clinical features of cavitary uveal melanoma. Retrospective chart review. Eight patients with cavitary uveal melanoma. The clinical, ultrasonographic, and histopathologic features of eight patients with cavitary melanoma of the ciliary body were studied. In all eyes there was a brown ciliary body mass that blocked transmission of light on trans-scleral transillumination. Ocular ultrasonography revealed a large, single hollow cavity (unilocular "pseudocyst") in five cases and multiple hollow cavities (multilocular "pseudocyst") in three cases. The cavity occupied a mean of 55% of the entire mass thickness (range, 31%-79%). In five cases, a basal uveal mass was noted on ultrasonography. Four patients underwent tumor resection; one had enucleation, and three had 125I radioactive plaque treatment. In the five cases confirmed histopathologically, the cavitation was empty, contained erythrocytes, serous fluid, and/or pigment-laden macrophages. In no case was the cavity lined by necrotic tumor, endothelial cells, or epithelial cells. Ciliary body melanoma can develop an intralesional cavity resembling an intraocular cyst. The presence of a solid mass at the base and a thick wall surrounding the cavity can assist in the differentiation of cavitary melanoma from benign cyst.