Abstract
Polycythemia vera (PV) is one of the myeloproliferative neoplasms and has higher frequency of the JAK2 V617F mutation. Hemorrhagic stroke is rare in PV, and myelofibrosis is secondary to PV. A 76-year-old Japanese man was diagnosed as PV with the JAK2 V617F mutation at the age of 63 years. He developed anemia together with secondary myelofibrosis, and then 40 mg ruxolitinib was started at 70 years. At 76 years, he presented with apathy and was diagnosed with intracerebral hemorrhage (ICH) in the right thalamus. Six months later, he developed multiple ICHs in bilateral cerebellar hemispheres. Leukocyte count was 57,600/μL, platelet count was 66,000/μL, and the level of hemoglobin was 8.7 g/dL. Bleeding time was 6 min. The agglutination ability when adding collagen was 41%. A patient with the JAK2 V617F mutation developing hemorrhagic stroke due to late-stage PV and secondary myelofibrosis was reported, implying various mechanisms for recurrent and multiple ICH.