FLT3 mutations at diagnosis and relapse in acute myeloid leukemia: cytogenetic and pathologic correlations, including cuplike blast morphology.

Context: Acquired mutations in the fms-like tyrosine kinase 3 gene (FLT3) adversely impact relapse risk after chemotherapy in patients with acute myeloid leukemia (AML). The FLT3 mutation status may differ at diagnosis and relapse, suggesting a potential role in chemoresistance, yet few reports have addressed the cytogenetic and pathologic correlates of FLT3 mutations in relapsed AML.

Objectives: To determine FLT3 mutations at diagnosis and relapse in a cohort of adult patients with chemoresistant AML and to correlate mutation status with multiple variables.