Therapy-related T-lymphoblastic lymphoma following acute myeloid leukemia remission with IDH2 mutation persistence

T-lymphoblastic lymphoma (T-LBL) is an uncommon hematological malignancy that rarely presents as a secondary cancer following chemotherapy. While IDH2 mutations are commonly identified in acute myeloid leukemia (AML), they were very rarely found in T-LBL. We present a case of an adult male diagnosed with therapy-related T-LBL with an IDH2 mutation after 3 years of complete remission following chemotherapy for AML with the same IDH2 mutation, which suggests a dedifferentiated multipotent cancer stem and progenitor cell that may give rise to both the myeloid and lymphoid malignancies.