Marked bone marrow eosinophilia at the time of relapse of acute myeloblastic leukaemia in association with the appearance of translocation t(12;20)(q24;q11).

We report a case of acute myeloblastic leukaemia (AML), FAB type M2, with karyotype t(8;21)(q22;q22), who at the time of relapse showed marked eosinophilia of the bone marrow. Karyotype analysis showed the appearance of an additional clone t(8;21)(q22;q22),t(12;20)(q24;q11). To the best of our knowledge, marked eosinophilia has not been reported in association with this particular chromosomal translocation.