Therapy-related acute myeloid leukemia developing 14 years after allogeneic hematopoietic stem cell transplantation, from a persistent R882H-DNMT3A mutated clone of patient origin.

Background: Therapy-related acute myeloid leukemia (t-AML) develops in patients with prior exposure to cytotoxic therapies. Selection of a pre-existing TP53 mutated clone prone to acquire additional mutational events has been suggested as the main pathogenic mechanism of t-AML. Here, we report a unique case of t-AML which developed from a pre-existing DNMT3A mutated clone that persisted in the patient for more than 10 years despite treatment with intensive chemotherapy and allogeneic hematopoietic stem cell transplantation (alloHSCT).