[Double t (3; 21) in acute myelomonocytic leukemia transformed from chronic myelomonocytic leukemia].

A 63-year-old male was diagnosed as chronic myelomonocytic leukemia with normal karyotype in September 1998. He developed acute myelogenous leukemia (AML-M4Eo) in September 2001. The cytogenetic analysis disclosed double t(3;21) at a ratio of 1/20, and the reverse transcriptase-polymerase chain reaction showed AML1/EVI-1 mRNA. He could not achieve complete remission after two courses of induction chemotherapy, and his leukemia cells carrying double t(3;21) were relatively increased. He died of interstitial pneumonia in December 2001. This is the first leukemia case with double t(3;21) and this chromosomal abnormality might play a role in leukemia cell proliferation by generating two AML1/EVI-1 genes.