Walter D. Foster

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.

Uveal melanoma: Location, size, cell type, and enucleation as risk factors in metastasis

In this series of 3,432 cases of malignant melanoma of the choroid and ciliary body, mortality from metastasis 15 years after enucleation was 46 per cent. This mortality was at least ten times greater than has been observed with tumors of the iris, probably owing to the greater size and more malignant cytology of choroidal and ciliary body tumors. In 56 per cent of the 3,432 cases, the melanomas were composed of a mixture of spindle and epithelioid cells. The 15-year mortality of patients with melanomas of mixed cell type was three times that of patients with tumors of pure spindle cell type. In 30 per cent of the cases in this series, the melanomas of the choroid and ciliary body were larger than 15 mm in diameter. Size was highly correlated with mortality. The distribution of deaths following enucleation in the 3,432 cases was a log-normal function of time from enucleation. This indicated that metastasis occurred in these fatal cases close to the time of enucleation. The authors were also able to infer that many years were usually required for these uveal melanomas to grow from small (7 to 10 mm in diameter) to large (greater than 15 mm in diameter). These observations are consistent with the hypothesis that dissemination of tumor cells at the time of enucleation has been a major cause of metastasis with small and medium-sized uveal melanomas.

Uveal melanomas: correlation of cytologic features with prognosis.

Forty uveal melanomas were examined, half of which had proved fatal. Twenty cells were selected from each tumor, and six cytologic features were measured on each of these cells. It was found that the cells selected from fatal tumors had longer nuclei, more nucleoli, and greater nuclear pleomorphism than those selected from nonfatal tumors. Also, cells from melanomas classified as mixed cell type by the Callender classification had wider nuclei and longer nucleoli than those from tumors classified as spindle B cell type. Since the former cell type is associated with a worse prognosis, these features would probably assist in assigning prognosis to a large group of randomly selected melanomas. Thus, five nuclear characteristics (long nuclei, wide nuclei, long nucleoli, multiple nucleoli, and nuclear pleomorphism) should prove useful for predicting death from the dissemination of uveal melanoma.