OBJECTIVETo investigate the clinicopathologic features of primary nodal marginal zone B-cell lymphoma (NMZL).

METHODSHematoxylin-Eosin staining and immunohistochemistry were used to evaluate the histological and immunophenotypic characteristics of lymph node (LN) tissue in 22 NMZL cases. Additionally, interphase fluorescence in-situ hybridization (FISH) was carried out to detect the presence of t(11;18) (q21;q21)/API2-MALT1 and/or t(14;18)(q32;q21)/IGH-MALT1 in 9 cases.

RESULTSThe median age of the 22 patients was 62 (16 - 77) ys. The male-to-female ratio was 1.2:1. All patients exhibited asymptomatic lymphadenopathy with the cervical region as the most often site to be involved (n = 11), followed by axillary (n = 9), inguinal (n = 7), submandibular (n = 6), mediastinal (n = 4), supraclavicular (n = 2) and retroperitoneal lymph nodes (n = 1). The Ann Arbor stages were I/II in 13 (59%) cases and III/IV in 9 (41%). Immunohistochemical study showed a consistently strong expression of CD20 and an absence in the expression of CD3ε, CD10, CD21, CD23, CyclinD1 and BCL6 by the tumor cells in all the cases. Frequency of expression of CD5 and BCL2 were 39% (7/18) and 30% (3/14) respectively. Among the 9 cases performed with FISH, 2 cases harbored t(14;18)and another 1 case positive for t(11;18) and t(14;18). Complete follow-up data were available for 13 cases. The follow-up time was 6 to 44 months. 3 of them died. 3-year cumulative survival rate was 67%.

CONCLUSIONSNMZL patients are often elderly, which mainly present with multiple lymphadenopathy, rare involvement of extranodal organ and early stage. The diagnosis must be based on a combination of clinicopathologic features, especially those patients detected t(11;18) and/or t(14;18).