der(8)t(1;8) in myeloblastic transformation of ET with hydroxyurea as the sole prior treatment

We described a patient with ET that evolved into MF and then subsequently developed myeloblastic transformation. A novel derivative chromosome der(8)t(1;8) was identified in the AML phase. The only prior treatment had been hydroxyurea. We hypothesized that AML in this case resulted from a complex pre‐disposition by the natural progression of ET, prolonged use of HU, and the prior evolution into MF. The leukemogenic risk of HU is critically appraised. Copyright © 2005 John Wiley & Sons, Ltd.