Abstract
Marginal zone lymphoma (MZL) is a heterogenous group of indolent non-Hodgkin lymphomas (NHLs). Three subtypes are recognized based on the site of involvement: extranodal MZL, splenic MZL, and nodal MZL. MZL represents 7% of all mature NHLs that exhibit geographical variability in their incidence and association with infectious agents. Each MZL subtype is characterized by unique biology, clinical presentation, therapeutic approach, and natural history. Recent findings have improved risk stratification of patients at diagnosis and after frontline therapy; however, these data are not incorporated into treatment decisions or selections of therapeutic agents. Moreover, a limited number of patients with MZL have been enrolled in randomized clinical trials, and all subtypes have been analyzed as a single group. This approach precludes a full characterization of the efficacy of treatment platforms, and current recommendations are largely derived from experience with follicular lymphoma. Emerging data have demonstrated that novel agents have higher efficacy and safety, expanding the landscape of treatment options. However, despite recent advances, several unmet needs remain in this field, including the discovery of prognostic biomarkers, utility of PET/CT at different extranodal sites, and appropriate sequence of therapies. There is a significant need to design clinical trials with the power to establish standard therapies as well as to assess their effects on patient-reported outcomes. In this review, we will provide an updated analysis of the literature and discuss our approach to the diagnosis and treatment of patients with MZL.