[Lymphoid blast crisis in chronic myelogenous leukemia].

A 70-year-old woman with PAS-positive acute lymphatic leukaemia was treated with vincristine, vindesine and prednisone. After three-month peripheral remission there developed mature-cell chronic myeloid leukaemia with positive Ph1 chromosome. After 12 days on busulphan (Myleran) treatment peripheral remission occurred for three months. After this there was again a lymphoid blast crisis with progressive development of a peripheral aplastic syndrome, of which the patient died 14 months after diagnosis of the first blast crisis. In retrospect, basophilia, spleen size and platelet count provided a pointer to the existence of a myeloproliferative syndrome even prior to the first blast crisis. Cytogenetic studies are recommended before treatment is started in every case of blast leukemia in order to assess any morphological change in the further course of the disease.