The relation between lymphosarcoma and leukemia.

Of 283 cases of lymphocytic disease, 81% fell within three distinct categories: lymphocytic and lymphoblastic lymphosarcoma and lymphocytic leukemia. The remaining 19% showed transitions from more mature to less mature cell types or from local to general anatomic distribution. The clinical course was related to the cell type and the extent of disease rather than to the presence of blood stream invasion. Survival of patients with lymphocytic leukemia and of those with lymphocytic lymphosarcoma was the same, while that of patients with lymphoblastic lymphosarcoma was much shorter. Survival curves are simple exponentials and do not suggest two populations, one with disease less malignant than the other.