Nodal marginal zone lymphoma designates a group of lymphomas, possibly heterogeneous, that appear to originate from a post-germinal centre B cell in the marginal zone that surrounds the mantle zone of lymph node follicles [1–3]. This lymphoma was previously known as monocytoid B-cell lymphoma. The clinical presentation is with lymphadenopathy. Some cases may be closely related to extranodal marginal zone lymphoma and others to splenic marginal zone lymphoma. An association with hepatitis C has been observed in a minority of patients .
By definition, disease is mainly nodal. It affects adults although a subtype of paediatric nodal lymphoma that manifests often as localized disease is recognized in the 2016 WHO classification . It appears that there is an increased incidence in patients with autoimmune diseases. Most patients present with advanced stage disease.
Haematological and pathological features
Bone marrow involvement is present in around a third of cases but the peripheral blood is rarely involved. The lymphoma cells are small to medium sized with a variable amount of cytoplasm, which is sometimes scanty and sometimes pale and abundant (monocytoid B cell). The nucleus is irregular. Some patients have a serum paraprotein.
In the lymph node, the lymphoma cells occupy the inter-follicular region or the marginal zone of residual follicles or both (Figures 8.1 and 8.2). Monocytoid B cells may be prominent but in other patients cells more closely resemble small lymphocytes. Follicular colonization can occur. Patterns resembling extranodal or splenic marginal zone lymphoma have been described.
Section of lymph node biopsy from a patient with nodal marginal zone lymphoma, showing marginal zone infiltration. Haematoxylin and eosin (H&E) stain, ×20 objective.
Section of lymph node biopsy from a patient with nodal marginal zone lymphoma, showing marginal zone infiltration, which is accentuated by immunohistochemistry for immunoglobulin D. Immunoperoxidase, ×20 objective.
Bone marrow infiltration may be random focal, paratrabecular or nodular. Intra-sinusoidal infiltration is uncommon. Neoplastic cells may be small or medium sized and sometimes have irregular nuclei and abundant pale cytoplasm.
Lymphoma cells express weak monoclonal immunoglobulin and B cell-associated antigens such as CD20, CD22, CD79a and CD79b. CD23 and/or CD43 may be positive but expression of CD5 is rare and cyclin D1 is negative. There is usually no expression of CD10 or BCL6. CD11c is sometimes expressed.
Cytogenetic and molecular genetic abnormalities
Cytogenetic analysis may show trisomy 18 or trisomy 3, as in splenic marginal zone lymphoma and mucosa-associated lymphoid tissue (MALT) lymphoma. In contrast to splenic marginal zone lymphoma, ...