Megakaryocytic blast crisis as first presentation of chronic myeloid leukemia.

We describe an extremely rare case of megakaryocytic blast crisis as first presentation of chronic myeloid leukemia. The patient had a very high platelet count and developed an ischemic stroke with seizures. She was treated with hydroxyurea, platelet apheresis, ARA-C, and idarubicin in order to obtain a prompt reduction of thrombocytosis and then with imatinib 600 mg/die PO. The therapy induced a complete hematological remission with a resolution of neurological signs within 4 weeks.