Novel case of coexisting TCF3 and IGH gene rearrangement in pediatric B-cell acute lymphoblastic leukemia: Favorable response to steroids and standard chemotherapy.

B-ALL, a genetically heterogeneous disease, is predominantly characterized by translocations leading to the formation of chimeric fusion proteins, which are known leukemia drivers. These driver fusions along with some driver mutations form an important basis for 11 distinct and mutually exclusive genetic subgroups by WHO. This classification besides providing important insights into distinct disease biology also provides important prognostic and therapeutic guidance. Coexistence of leukemia fusion drivers in B-ALL is a rare event and literature evidence with respect to clinical outcome of such patients remains elusive. We report a rare case of pediatric B-ALL with coexistence of TCF3 and IGH gene rearrangement. The patient responded well to induction chemotherapy with good response to steroids. Minimal residual disease was negative postinduction. The patient is presently under follow-up and remains in remission ~28 months post diagnosis. This case adds to our understanding of such rare phenomenon and enlighten us the response to chemotherapy in such circumstances.