Although the karyotype is usually normal, occasional otherwise typical patients exhibit the Ph' chromosome. There is no staging system for this disease. Untreated essential thrombocythemia Untreated essential thrombocythemia means that a patient is newly diagnosed and has had no prior treatment except supportive care. The myeloproliferative disorders, excluding chronic myelogenous leukemia, are chronic diseases with a variable propensity to convert into acute myelogenous leukemia. Patients with polycythemia vera and essential thrombocythemia have marked increases of red cell and platelet production, respectively.
Treatment is directed at reducing the excessive numbers of blood cells.
Some citations in the text of this section are followed by a level of evidence. The PDQ editorial boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. Refer to the PDQ levels of evidence summary for more information. In addition, progressive splenomegaly or pruritus not controllable by antihistamines may persist despite control of the hematocrit by phlebotomy. If phlebotomy becomes impractical, therapy with the radioisotope phosphorous-32 or alkylating agents can be used to control the disease.