Leukemic presentation of high-grade B cell lymphoma with MYC and BCL2 rearrangement—a series of two cases and review of literature

Abstract

High-grade B cell lymphoma (HGBL) is a recently introduced category of aggressive mature B cell lymphoma which is clinically and biologically distinct from diffuse large B cell lymphoma (DLBCL), NOS, and Burkitt Lymphoma. HGBL consists of two categories; the first category includes HGBL with MYC and BCL2 and/or BCL6 rearrangement which is so-called double or triple hit lymphoma. The second category includes HGBL, NOS which lacks genetic double or triple hit; however, its morphology is intermediate between DLBCL and Burkitt lymphoma or appear blastoid. Clinically, patients present with advanced disease, bone marrow involvement, elevated lactate dehydrogenase (LDH), extranodal disease which includes CNS involvement and a high international prognostic index (IPI). Leukemic presentation has been described in various types of B and T cell non-Hodgkin lymphoma; however, peripheral blood involvement as an initial presentation is seldom described in the literature for HGBL with MYC and BCL2 rearrangement. Here, we report two cases of HGBL whose initial presentation was leukocytosis with peripheral blood involvement mimicking acute leukemia.