nodal marginal zone B-cell lymphoma (MONDO_0019465, a Monarch Disease Ontology identifier) is a rare, indolent B-cell non-Hodgkin lymphoma, characterized by abnormal clonal proliferation of mature B-lymphocytes with involvement of the lymph nodes, sometimes the bone marrow, and rarely the blood. Clinically it presents with disseminated peripheral, abdominal and/or thoracic lymphadenopathy. Cytopenia and bulky tumors (greater than 5 cm) are rare. Association with Hepatitis C virus and chronic inflammation has been reported. Also known as: Monocytoid B-cell lymphoma, NMZL, nodal marginal zone B-cell lymph., nodal marginal zone lymphoma.