Prognostic value of nucleolar size and size pleomorphism in choroidal melanomas

Morphometric estimates of nucleolar size have been shown to possess a high prognostic value in patients with uveal melanomas. The authors investigated various quantitative estimators of the mean size and pleomorphism of nucleoli in choroidal melanomas from a consecutive series of 95 Danish patients treated solely by enucleation of the melanoma-bearing eye in the period from 1977 to 1979. The independent prognostic value of the quantitative histopathological variables was evaluated using multivariate Cox analysis. Apart from patient data and information about tumor extent, histological type of melanoma, and largest macroscopic tumor dimension (LTD), the following histomorphometric estimates were obtained: mean diameter of the 10 largest nucleoli (MLN), point-sampled mean nucleolar profile area (nucleolar ao) and the associated standard deviation of nucleolar ao, the volume-weighted mean nucleolar volume (nucleolar vv), and associated variance and relative variance of nucleolar volume (nucleolar Varv(v) and nucleolar CVv(v), respectively). The intra-observer reproducibility of estimates of nucleolar vv was tested in 20 cases and found acceptable (r = 0.84, 2p = 3.6.10(-6)). Correlation analysis indicated that estimates of nucleolar vv and nucleolar Varv(v) are identical in choroidal melanomas, except for a scaling factor. There were no differences of the grouped means of histomorphometric estimates in choroidal melanomas that showed intra- or extra-ocular extension (2p > 0.13). LTD was of the same magnitude in all histological types of melanoma (2p = 0.69). Estimates of nucleolar vv and associated estimates of nucleolar volume pleomorphism were increased in melanomas of the mixed and epitheloid cell type (2p < 0.005). Single factor analyses showed that all quantitative histopathological variables were of prognostic value in the studied patients, in addition to the histological type of tumor. However, using multivariate analysis, only estimates of LTD, MLN, nucleolar vv, and of nucleolar volume pleomorphism had independent prognostic value.