[Philadelphia chromosome-positive chronic myeloid leukemia with washing out of Ph'-negative lymphoid blasts and with meningiosis: atypical blast crisis or a 2d leukemia?].

The case of a 53-year-old female with a Philadelphia-chromosome (Ph')-positive chronic myeloid leukemia (CML) is reported. In this patient, a first lymphoid blast crisis developed after a chronic period of 20 months. Treatment with vincristine and prednisone was successful. A few weeks later she presented with meningeal leukemia with lymphoid blastic cells in CSF and a facial nerve palsy, while the peripheral blood showed the typical picture of CML. Meningeal leukemia was successfully treated with cranial irradiation and intrathecal chemotherapy. Later on, a second lymphoid blast crisis (blasts of "common acute leukemia" type) was observed. Again, chemotherapy with vincristine and prednisone was successful. After 2 1/2 weeks, however, a third lymphoid blast crisis developed. At this moment, Ph'-chromosome was undetectable in unstimulated cells of the peripheral blood. The question of an additional leukemia is discussed.