A histopathological study on the prognosis and radiosensitivity of retinoblastoma.

It has been observed that a tumor which is well differentiated has, in general, a better prognosis than a less differentiated tumor. Presumably, this is accounted for by the fact that the more differentiated type develops and grows more slowly, consequently making it a somewhat less malignant type of lesion. 1 Another general observation has been made from the standpoint of treatment with radiotherapy and chemotherapy. Specifically, it would seem that while the less differentiated cell type is more malignant, it is at the same time more readily responsive to treatment. The association between differentiation and prognosis has already been made by Callender and Wilder in their work on uveal melanoma. 2-5 According to them, the heavier the argyrophil fiber content of the tumor, the better the prognosis. Thus, they found that spindle-cell tumors have the best prognosis while the epithelioid cell tumors have the poorest prognosis. This association has