INTRODUCTION
Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma in adults, while it is rare in children. DLBCL is a heterogeneous subtype of mature B-cell lymphoma characterized by the diffuse proliferation of B-cell antigen-expressing lymphoma cells larger than histiocyte nuclei. DLBCL is associated with frequent gene translocations, such as IGH -BCL6 , IGH -BCL2 , and IGH -MYC .1
KMT2A rearrangement is associated with leukemogenesis in acute lymphoblastic leukemia (ALL) and acute myeloid leukemia. KMT2Arearrangement in acute leukemia accounts for 5–10% of the total cases and correlates with poor prognosis.2 However,KMT2A -rearranged lymphoma has not been studied in detail.KMT2A -rearranged lymphomas, especially KMT2A- rearranged DLBCL, are less frequent than KMT2A -rearranged leukemia and the majority of those is constituted by lymphoblastic lymphoma.3-8 KMT2A -rearranged DLBCL can be detected in a few adult and pediatric patients.9,10
Herein, we describe a pediatric case of KMT2A -rearranged DLBCL. We performed RNA sequencing (RNA-seq) to understand the molecular biology of KMT2A -rearranged DLBCL.