Nonfollicular small B-cell lymphomas: a heterogeneous group of patients with distinct clinical features and outcome.

Two hundred sixteen patients with a nonfollicular small cell lymphoma followed up in our department over a 5-year period have been reviewed to define the clinical behavior and survival of patients with each histologic subtype. The respective frequencies of major subtypes were: small lymphocytic/lymphoplasmacytoid lymphoma (immunocytoma, SL/LPL), 28%; large cell-rich immunocytoma (LCRI), 7%; mantle cell lymphoma (MCL), 24%; mucosa-associated lymphoid tissue-lymphoma (MALT-L), 20%; other rare subtypes, 6%; and nonclassified or nonreviewed, 14%. The SL/LPL patients and the MALT-L patients had a relatively indolent disease, usually disseminated for SL/LPL and usually localized for MALT-L. Both subtypes have a long time to treatment failure (TTF; median, 48 and 58 months, respectively) and long survival (median, 118 and 98 months, respectively). The LCRI patients or the MCL patients had more aggressive clinical or biologic features and experienced shorter TTF (median, 26 and 14 months, respectively) and shorter survival (median, 55 and 52 months, respectively). None of these histologic subtypes was associated with a significant cure rate. MALT-L patients did relapse regardless of the initial localization or treatment and at a similar rate to the SL/LPL patients. Factors associated with a worse outcome in nonfollicular small cell lymphoma patients are identical to those described in other lymphoma subtypes: advanced clinical stage, poor performance status, high tumor bulk, and high lactic dehydrogenase or beta 2microglobulin levels. For patients with disseminated disease, standard chemotherapy regimens did not allow a long TTF; therefore, new therapeutic strategies must be developed.