a patient with myelodysplastic syndrome and acute myeloid leukemia evolving from polycythemia Vera (PV) treated with hydroxyurea for 4 years.
A 43-year-old man presented with facial erythrosis and intense itching in June 1991. Physical examination revealed splenomegaly. Complete blood count revealed a red blood count of 8.4 X 10'2/1, hemoglobin of 24 gldl, hematocrit of 72.1%, white blood count (WBC) of 18 X 109/1, and a platelet count of 218 X 109/l. According to standard criteria the diagnosis of PV was made. In an attempt to promptly restore a normal red-cell mass, phlebotomy was performed. Four months later, the platelet count rose above 600 X 109/1, and the patient was then treated with hydroxyurea. The patient received between 1,000-2,000 mg/day with excellent control of blood counts. After 4 years of therapy with hydroxyurea he developed pancytopenia. The dose of hydroxyurea was decreased but the cell counts worsened and he developed bone pain, asthenia, and splenomegaly. The hydroxyurea was stopped, and a bone-marrow examination was performed, revealing massive trilineage hyperplasia with marked cytologic abnormalities, 27% of ringed sideroblasts, and a 20% increase of immature myeloid forms. Cytogenetic analysis revealed -1, -5, -9, -17,7p+, 12p+, de1(17)(q23). Ten days later the WBC rose to 81 X 109/l. Bone-marrow examination was repeated and revealed acute myeloid leukemia, FAB type M5. He was induced with doxorubicin and cytosine arabinoside (3 + 7 regimen), but