Transformation of reticulum cell sarcoma to acute leukemia

Two patients with leukemic transformation of reticulum cell sarcoma are described. The interval from initial diagnosis of reticulum cell sarcoma to development of leukemia was 4 months in one patient and 1 year in the other. Central nervous system involvement occurred in both patients. The patients died shortly after the development of leukemia and administration of combination chemotherapy. Eight additional well‐documented cases of reticulum cell sarcoma transformation to acute leukemia are summarized from the literature. Radiotherapy, administered to all but one of these cases, could not be implicated in the pathogenesis of leukemic transformation because of the short latent period between irradiation and development of leukemia. The differentiation of leukemic transformation of reticulum cell sarcoma from granulocytic sarcoma and leukemic reticuloendotheliosis is discussed.