The occurrence of acute leukemia in patients with chronic lymphocytic leukemia is being reported with increasing frequency. 1-31 Although the majority of these cases have been described as "acute blastic terminal phase" or as straightforward lymphoblastic in nature, a substantial number of patients' terminal acute leukemia has been described as myeloblastic, monocytic, and myelomonocytic, which raises the question of a separate origin to this terminal acute leukemia. A review and analysis of the literature are the substance of this report. LITERATURE REVIEW In 1949, Lawrence et al 1 described 100 patients with chronic lymphocytic leukemia treated with radioactive phosphorus ( 32 P). Fifty-eight of the patients also received local radiation to spleen or lymph nodes either prior to or subsequent to the 32 P therapy. Two of the 100 patients developed "acute leukemia with increased numbers of blast cells in the blood smear" (type not stated). The following year, another report