Acute lymphoblastic leukemia with clonal evolution due to delay in chemotherapy: A report of a case.

Clonal evolution in acute leukemias is one of the most important factors that leads to therapeutic failure and disease relapse. Delay in therapeutic intervention is one of the reasons that leads toward clonal evolution. In this report, we present a case of acute lymphoblastic leukemia in which therapeutic delay resulted in clonal evolution that was detected by conventional karyotyping and was responsible for non-responsiveness of the disease to conventional chemotherapy.