Metastatic uveal melanoma. Correlation between survival time and cytomorphometry of primary tumors

The length of survival time following enucleation was determined for 29 patients with primary malignant melanoma of the choroid and ciliary body who subsequently died of metastatic disease. Histologic sections of the 29 tumors were studied by standard light microscopic techniques and computerized morphometry. The largest diameter of each tumor was measured on the 37% formaldehyde-fixed, paraffin-embedded slides; a cell type was assigned to each tumor on the basis of histologic study, using the modified Callender cell-type classification system; and inverse standard deviation of the nucleolar area (ISDNA) was determined for each tumor by computerized morphometric analysis. The observed death-order of these patients was then compared with the death-order predicted by ranking cases in ascending order of age at treatment, size of tumor, cell type, and ISDNA. Using rank-order correlation coefficient tests, only the correlation between ISDNA rank-order and observed death-order was found to be statistically significant. We believe that the limitations of the modified Callender cell-type classification system in predicting length of survival time following enucleation are related to the relatively few categories (four) in which to classify tumors, whereas the ISDNA represents a continuous spectrum of unlimited categories. As such, ISDNA can be more discriminant in selecting tumors of high malignant potential.