Changes to This Summary (02 / 15 / 2013)
Revised text to state that painful splenomegaly can be treated temporarily with ruxolitinib, hydroxyurea, thalidomide, lenalidomide, cladribine, or radiation therapy, but sometimes requires splenectomy.
Added text to state that after splenectomy, many physicians use anticoagulation for 4 to 6 weeks to reduce portal vein thrombosis, and hydroxyurea can be utilized to reduce high platelet levels (cited 2006 Mesa et al. as reference 33); however, data from a retrospective review of 150 patients who underwent surgery provided documentation that 8% of the patients had a thromboembolism and 7% had a major hemorrhage with prior cytoreduction and postoperative subcutaneous heparin used in one-half of the patients (cited Ruggeri et al. as reference 34).
Added text to state that allogeneic stem cell transplantation is the only curative treatment available for splenomegaly, but the morbidity and mortality limit its use to younger high-risk patients (cited Gupta et al. as reference 44); detection of the JAK2 mutation after transplantation is associated with a worse prognosis (cited Alchalby et al. as reference 45).
Revised the list of treatment options for primary myelofibrosis.
Added text to the World Health Organization criteria to state that a finding distinguishes essential thrombocythemia from another entity with thrombocytosis, and patients with prefibrotic primary myelofibrosis have a worse survival than patients with essential thrombocythemia because of an increased progression to myelofibrosis and increased progression to acute myelogenous leukemia (cited Passamonti et al. and Barbui et al. as references 2 and 3). Also revised a criterion to read demonstration of JAK2 V617F mutation or MPL exon 10 mutation, adding that in the presence of a JAK2 or MPL mutation and with the exclusion of other myeloproliferative or myelodysplastic features, a bone marrow aspirate/biopsy may not be mandatory for a diagnosis (cited 2010 Harrison et al. as reference 5).
Revised text to state that patients older than 60 years or those with a prior thrombotic episode or with leukocytosis have as much as a 25% chance of developing cerebral, cardiac, or peripheral arterial thromboses and a chance of developing a pulmonary embolism or deep venous thrombosis (cited 2012 Harrison et al. as references 7).