Post-polycythemia myeloid metaplasia: experience with a large cohort of patients.

The common origin of myeloproliferative disorders can explain the possible evolution of polycythemia vera to post-polycythemia myeloid metaplasia (PPMM). Such a possible event is usually considered linked to the use of myelosuppressive agents in particular 32P. Occasionally, myelofibrosis following essential thrombocythemia has also been described. We report here 19 cases of post-polycythemia myeloid metaplasia out of 214 polycythemia vera patients (8.8%). The majority of these patients received 32P therapy. However, busulfan also seems to have some role in the modification of polycythemia vera. In particular, the association of more than one myelosuppressive agent may favour the evolution of PPMM.