1. A case of promyelocytic-myelocytic leukemia is reported as the terminal phase of chronic granulocytic leukemia. We believe that this is the first such case reported.
2. The terminal phase of this case is compared with acute promyelocytic-myelocytic leukemia; the course and laboratory data appear almost identical.
3. The nature of the abnormal granules in the promyelocytoid-myelocytoid cells and their relation to the fibrinogenopenia incite speculation.