CD56-positive diffuse large B-cell lymphoma/leukemia with BCL6/MYC double-hit and multiple gene mutations: an indicator of poor prognosis?

Diffuse large B-cell lymphoma (DLBCL) is the most common adult non-Hodgkin lymphoma (NHL) and is highly invasive, with a poor prognosis. The main clinical treatment for DLBCL involves chemotherapy or a combination of chemotherapy and targeted drugs. CD56 expression is considered as an indicator of poor prognosis in patients with acute myeloid leukemia and anaplastic large cell lymphoma; however, its role in DLBCL remains unclear. We report on a patient with CD56-positive DLBCL/leukemia with BCL6/MYC double-hit, and DDX3X, LRP1B, SIN3A, and GNA13 gene mutations (stage IVA, prognostic index aaIPI = 2 points). The patient was treated with cyclophosphamide and prednisone pre-chemotherapy plus R-Hyper-CVAD AB and DA-EPOCH regimens. Lumbar puncture combined with intrathecal injection was performed to prevent central nervous system infiltration during hospitalization, and complete remission was confirmed. We also reviewed the literature to clarify the relevance of the unique clinical features associated with this case.