Nodal marginal zone lymphoma.

Nodal marginal zone lymphoma (NMZL) is one of the three well-recognized entities within the broad category of marginal zone lymphoma, representing approximately 10% of the cases in this group. Patients typically present with nodal disease, usually at advanced stages, and a thorough work-up and staging are necessary in order to exclude occult extranodal involvement. NMZL shares many similarities with splenic marginal zone (SMZL) and mucosa-associated lymphoid tissue (MALT) lymphomas, such as cytology, immunophenotype, genetic abnormalities and maybe even a common cell of origin: a post-germinal memory B-cell. NMZL is characterized by an indolent course, but its prognosis is generally considered less favorable than that of SMZL and MALT lymphoma, with reported 5-year overall survival rates ranging between 55% and 89%. Therapeutic recommendations for NMZL are derived from small retrospective series or studies on larger cohorts of indolent lymphomas, which include a limited number of patients with NMZL. For localized disease, radiotherapy appears to be the treatment of choice, while rituximab-containing therapy is recommended for advanced stage disease. Due to the rarity of NMZL it is very difficult to perform prospective trials, and an international collaborative effort is necessary in order to better understand the biological features and provide evidence-based treatment recommendations.