bcr-abl hybrid messenger RNA in a patient with Philadelphia-negative essential thrombocythemia

We describe a case of Philadelphia-negative essential thrombocythemia in whom bcr-abl hybrid messenger RNA was detected. The patient suffered from frequent splenic infarctions and myelofibrosis. Interestingly, a transformation to acute leukemia which was commonly seen in patients with bcr-abl-positive chronic myelogenous leukemia did not occur until he died from heart failure due to severe anemia 8 years after the diagnosis. The heterogeneity of bcr-abl-positive thrombocythemia is emphasized.