Non-Hodgkin's lymphomas of primary follicle/mantle zone origin.
Recent immunopathologic studies have demonstrated that primary follicles and the mantle zones of secondary follicles are composed largely of virgin B lymphocytes which migrate from the bone marrow to these areas, and are the precursor cells of germinal centers. Non-Hodgkin's lymphomas corresponding to these immature B cells include mantle zone lymphoma (MZL), a primary follicle variant of MZL without reactive germinal centers, and diffuse intermediate lymphocytic (centrocytic) lymphoma. Diffuse intermediate lymphocytic lymphoma (DILL) is considered a late stage in the progression of MZL. Cytologically, these lymphomas usually resemble their normal cellular counterparts and consist predominantly of atypical small lymphoid cells with slightly-irregular and indented nuclei, moderately-coarse chromatin, inconspicuous nucleoli, and scant cytoplasm. Small lymphocytic, cerebriform and blastic variants have also been described. In smears and touch preparations, the neoplastic cells are usually prolymphocytes. Immunologically, the cells have features of virgin B cells, bearing pan-B cell antigens along with monoclonal surface IgM, with or without surface IgD, and CD5 (Leu 1) antigen, and lacking common acute lymphocytic leukemia associated (CALLA) antigen. Cytogenetically, the t(11;14)(q13;q32) has been associated with this group of lymphomas, and expression of the putative cellular oncogene bcl-1 (11q13) has been demonstrated in 30-50% of cases. Clinically, the patients have a median age of 60 years and usually present with advanced stage disease. Splenomegaly, often massive, is present in 80% of those with MZL. Patients with MZL have a significantly longer median survival (74-77 months) than those with DILL (30-33 months), and survival in both groups is significantly prolonged if a complete clinical remission is attained. Based on clinical studies, MZL should be considered a low grade lymphoma and DILL should be considered an intermediate grade lymphoma by Working Formulation criteria. The lymphomas of primary follicle/mantle zone origin are a distinct clinicopathologic entity biologically analogous to the follicular and diffuse lymphomas of germinal center origin, from which they should be distinguished in current and future classifications of non-Hodgkin's lymphoma.
Weisenburger
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Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha 68198.
D015703:Antigens, CD / Q000032:analysis; D018956:CD5 Antigens; D002454:Cell Differentiation; D002869:Chromosome Aberrations / Q000276:immunology / Q000473:pathology; D025063:Chromosome Disorders; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D016019:Survival Analysis
D015703:Antigens, CD; D018956:CD5 Antigens