[Leukemic transformation of polycythemia vera after treatment with hydroxyurea and chromosome 17 abnormalities].

The authors present two patients with polycythemia vera where they recorded after several years' treatment with hydroxyurea development of acute myeloblastic leukaemia. In both instances they found, associated with leukaemia, abnormalities of chromosome no.17, in one case meeting criteria of the so-called 17p-syndrome. Progression of polycythemia vera into acute leukaemia is explained by the possible association with the long-term use of the drug and loss of chromosomal material (short arm of chromosome 17), the part where genes important in the process of leukaemogenesis are located. The authors draw attention to contemplated long-term administration of hydroxyurea to young patients with polycythemia vera. As cytogenetic analysis is a suitable method for evidence of progressing polycythemia vera into acute leukaemia, dynamic follow up of chromosomal changes is necessary, in particular in patients where long-term treatment with hydroxyurea is assumed.