Lymphosarcoma is a malignant neoplastic disease of lymphoid tissue capable of arising in any lymphoid aggregate. It may run an acute or chronic course and is almost invariably very radiosensitive. An apparent cure is possible but the disease is much more likely to terminate in death, at which time the wide extent of clinically unsuspected metastases may be astonishing. With Hodgkin's disease and lymphatic leukemia, it comprises a group of tumors of relatively low morbidity, the high mortality and often strikingly similar clinical and pathologic pictures of which have properly earned them the designation "malignant lymphomas." The term "lymphoblastoma" (Desjardins,1Minot and Isaacs2) has gained considerable popularity as a means of rather loosely conjoining a number of conditions of which lymphosarcoma and Hodgkin's disease make up the majority. The practicality and convenience of any term aimed at accomplishing such a linkage cannot be denied when applied to individual