[Acute transformation in 45 cases of chronic myeloid leukemia]

After a chronic phase, the average duration of which in this series was 38 months, the acute phase of myeloid leukemia was very short, not exceeding 7 months. The clinical signs which suggest an acute exacerbation are, in order of importance, increase in the volume of the spleen, changes in general health, fever. The blood signs, which are often found later than the clinical signs, are increased white cell count, anemia and marrow leukoblastosis higher than 20%. The laboratory criteria of acute exacerbation are of lesser importance. Chemotherapy gives very poor results at this stage.