Electron Microscopy of Uveal Melanoma

Abstract

Uveal melanomas have been shown by ordinary microscopy to vary in malignancy according to their cytology. Tumors containing epithelioid cells are associated with a poorer prognosis than are tumors containing only spindle cells.^1-5 The present paper, based on a study of 12 cases, is an investigation into the ultrastructural characteristics of spindle and epithelioid cells in uveal melanoma. The present literature on this subject consists of four reports, three of which are of single cases.^6-9 In several areas the existing reports do not agree. This may be because the cytology of uveal melanoma presents a broad spectrum rather than a study of sharply defined types. Materials and Methods Twelve uveal melanomas were obtained from freshly enucleated adult human eyes. In each case the globe was quickly opened and pieces of tissue, 2 sq mm, were excised from central and peripheral areas of the tumor. Fixation was in cold