RESUMO
An 80-year-old man received a diagnosis of anemia and a decreased platelet count from his physician in 2008, and was referred to our department where primary myelofibrosis was diagnosed.The patient was classified into the lower risk group according to the International Prognostic Scoring System(IPSS), and was followed up without treatment.In June 2010, pancytopenia progressed, and the patient was reclassified into the higher risk group.Blood count did not increase with metenolone treatment, but increased with zoledronic acid(ZA)that he started receiving from January 2012. After ZA treatment, circulating levels of vascular endothelial growth factor(VEGF)and transforming growth factor-b(TGF-b)decreased, and bone marrow biopsy showed an absence of reticular fibers and collagen fibers.In the present case, we observed that the blood count increased because of ZA-induced improvements in myelofibrosis.