- The following histologic types by REAL classification and International Working Formulation (IWF) when applicable (NOTE: Closed to accrual as of 10/29/07): Small lymphocytic lymphoma; Lymphoplasmacytoid lymphoma; Follicular center lymphoma, follicular grades 1, 2, and 3; Extranodal marginal zone B cell lymphoma of MALT type; Nodal marginal zone B cell lymphoma