[MYC-associated B-cell lymphomas: pathophysiology and treatment].

The outcome of double-hit lymphoma (DHL) defined by concurrent rearrangements of MYC and BCL2 and/or BCL6 is extremely poor than that of diffuse large B-cell lymphoma (DLBCL). Patients with DHL are usually resistant to R-CHOP therapy and show a highly aggressive clinical course frequently involving the extranodal sites, such as the bone marrow, peripheral blood, pleural effusion, and central nervous system (CNS). However, several retrospective studies conducted recently have demonstrated a relatively favorable outcome with intensive chemotherapy, such as dose-adjusted EPOCH-R, than those receiving R-CHOP in patients with DHL. "Double expressor status" with concomitant expression of MYC and BCL2 protein by immunohistochemistry in DLBCL is considered a poor prognostic biomarker and has been associated with high risk of CNS relapse. Therefore, to reduce these risks, CNS-directed evaluation and consideration of CNS-prophylactic strategies should be performed in patients with double expressor lymphoma. This chapter reviews the clinical and pathological features, prognosis, treatment strategies, and new insights in MYC-associated B-cell lymphoma, such as Burkitt lymphoma.