A comparison of prognostic covariates for uveal melanoma.

For 740 selected cases of uveal melanoma from the Armed Forces Institute of Pathology, the following features were determined: the age and sex of the patient, Callender cell type (CT), and largest tumor dimension (LTD). In addition, special morphometric devices were used to measure the standard deviation of nucleolar area (SDNA) and the mean of the largest nucleoli (MLN) from a single routine hematoxylin and eosin-stained section of each tumor. Univariate analysis using the Cox proportional-hazards model revealed that LTD, CT, SDNA, and MLN correlated equally with death from metastatic melanoma (P greater than 10(-6). Age correlated less highly (P less than 0.002), and sex had no relationship to mortality. Multivariate analysis revealed that adding LTD as a prognostic covariate to either CT, SDNA, or MLN yielded a substantial increase in prognostic value. Because MLN can be measured more easily than SDNA and is more reproducible than CT, it can be a useful cytologic index of the malignant potential of uveal melanomas.