Reassessment of non-Hodgkin's lymphoma with a "nodular" growth variant: a clinicopathologic study of follicular, mantle cell and marginal zone lymphomas prospectively diagnosed with multiparameter analyses

Although three subtypes of non-Hodgkin's lymphoma (NHL), follicular lymphom a (FL), mantle cell lymphoma (MCL) and marginal zone lymphoma (MZL), are no w well recognized as independent categories, their biological behavior has not been fully compared. One of the reasons for this may be that subclassif ication by histological examination alone is often difficult since they all have a common variant of a "nodular" growth pattern and occasionally show similar cytological morphology. Recently, we reviewed patients with FL, MCL and MZL, who were prospectively diagnosed, using multiparameter analyses w ith unfixed fresh biopsy materials. Of 407 NHL patients, 101 (24.8%) belong ed to these three categories and 80 could be followed; FL (n=27), MCL (n=27 ) and MZL (n=26). Twenty eight cases with diffuse large B-cell (DL-B) linea ge lymphoma were selected as control at random. The frequency of the MCL patients with performance status (PS) 2 to 4 (41%) was significantly higher than MZL patients (4%) [P<0.001]. The 3 year surv ival rate with FL, MCL, MZL and DL-B was 71.5%, 57.4%, 93.3% and 53.1%, res pectively. The survival rate for MZL was significantly better than both FL (p = 0.048) and MCL (p = 0.0085). Significant differences were also found i n the overall survival rates among the four risk groups as defined by the I nternational Index Il Ll(low, low-intermediate, high-intermediate and high; 97.4%, 79.6%, 39.4% and 18.2%, respectively). A multivariate analysis reve aled that the Internatinal Index may be a significant predictor for short s urvival (p=0.0001) in the patients with FL, MCL or MZL. These results sugge st that MZL shows an apparently better prognosis than FL and MCL and is fou nd to be a prognostically independent category. In contrast, the clinical o utcome in MCL is the worst among the three subtypes and was closer to that of DL-B. The International Index can be applied to a wide spectrum of NHL, including MCL, MZL and FL, to and can predict prognosis in these cases.