Modifications of Callender's classification of uveal melanoma at the Armed Forces Institute of Pathology

One hundred well-documented cases of uveal melanoma accessioned at the Armed Forces Institute of Pathology before 1970 were reviewed and reclassified to identify changes made in the Callender classification. We compared the new classification with the original classification to determine the effect of the changes on the prediction of outcome for the patient after enucleation. Staff pathologists had originally classified 52 of the 100 cases as spindle-cell type melanoma. Only 31 of the 100 cases were reclassified as spindle-cell types (two spindle-cell nevi and 29 spindle-cell melanomas). Tumors classified as mixed-cell type were further subdivided into groups based on the percentage and size of the epithelioid cells. Tumors formerly classified as spindle-cell type that contained small or rare epithelioid cells were reclassified as mixed-cell type. This improved the prediction of outcome for the patient. We found that nucleolar size and pleomorphism are important variables that should be considered in the classification of uveal melanomas.