Nodal marginal zone lymphoma: current knowledge and future directions of an heterogeneous disease.

Nodal marginal zone lymphoma (NMZL) is a defined, separate clinicopathological entity. NMZL is a B-cell neoplasm originated in the lymph node, whose histology resembles the nodal infiltration by mucosa-associated lymphoid tissue- or splenic-type marginal zone lymphoma, in the absence of clinical evidence of extranodal or spleen disease. The lack of characteristic phenotypic or molecular diagnostic findings is still hampering the reproducibility of this diagnosis. Herein, we review the main morphological and immunophenotypical markers, discussing the differential with other overlapping entities. We also summarize the clinical features and outcome of this rare lymphoma and we discuss the possible association with hepatitis C virus infection.