SEER is an authoritative source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.
The t(8;21)(q22;q22) translocation juxtaposes the AML1 gene on chromosome 21 to the ETO for t(I;21) gene on chromosome 8, which results in the production of the AML-ETO fusion protein. AML with t(8;21)(q22;q22) is an acute myeloidleukemiagenerally showing maturation in the neutrophil lineage. This translocation is one of the most common (5-12% of AML cases). Myeloid sarcomas (chloromas) may be present and may be associated with a bone marrow blast percentage of less than 20%. If translocation present, categorize as AML even if initial blast count is < 20%.
Tumor manifestations such as myeloid sarcomas may be present at diagnosis; in these cases an initial BM aspiration may show a misleading low number of blast cells but should be diagnosed as AML despite a blast percentage in BM of less than 20. Smaller blasts may be found in the PB.