Isolated ovarian metastasis from a spindle cell malignant melanoma of the choroid 14 years after enucleation: prognostic implication of the keratin immunophenotype

A 47-year-old woman developed metastatic melanoma to the right ovary 14 years after the enucleation of the right eye for a choroidal spindle cell melanoma. An immunohistochemical study was performed on paraffin sections of both primary and metastatic melanoma specimens to identify markers of both aggressive phenotype and metastatic potential with particular attention to the anomalous expression of cytokeratin intermediate filament proteins. Neoplastic cells of both primary and metastatic tumors immunostained positively for S-100, HMB45, MART-1, and vimentin antibodies, but they were negative for cytokeratins 1-19, 8, 18, and 8,18; <10% of neoplastic cells in both the primary and the metastatic melanomas immunostained for Ki-67 proliferating antigen using MIB-1 antibody. We speculate that the indolent behavior of this ovarian metastasis is reflected by the absence of coexpression of cytokeratins 8 and 18 with vimentin. This case supports the practical value of using this panel of antibodies to evaluate the aggressive potential of uveal melanomas.