Blastic Crisis of Primary Myelofibrosis Associated with Multiple Myeloblastomas

Abstract

The patient is a 71-year-old female who underwent splenectomy due to splenomegaly 32 months after diagnosed as having primary myelofibrosis. On examination she was found to have massive skin nodules, lymph nodes swelling and an enlarged liver with an abnormal hematologic profile as follows: RBC count 3.68×10⁶/μl; WBC count 151×10³/μl with 11% blasts; and platelet count 42×10³/μl. The bone marrow aspirate showed a hypocellular marrow with 19.2% blasts. Histological examination of the skin nodules revealed that they were myeloblastomas, thus suggesting leukemic transformation of primary myelofibrosis. Her WBC count dropped to about 20×10³/μl through treatment with vindesine, cyclophosphamide, 6-mercaptopurine and prednisolone, but it did not drop further.
Treatment with dexamethasone remarkably regressed the myeloblastomas, but she died of heart failure 4 months after diagnosis of leukemic transformation of primary myelofibrosis. The autopsy findings showed the formation of numbers of myeloblastomas in both the systemic fatty tissue and dura mater as well as extramedullary hematopoiesis in liver and lymph nodes.
A rapid development of splenomegaly in a patient with primary myelofiblosis seems to be associated with leukemic transformation.