Five cases of intermediate lymphocytic lymphoma (ILL), 13 cases of malignant lymphoma centrocytic (MLCC), and 27 cases of malignant lymphoma centroblastic centrocytic (MLCBCC) were studied morphologically and with the aid of a panel of monoclonal antibodies. The immunophenotypes of ILL and MLCC (IgM+/IgD+, MT1+, CALLA-) indicate a mantle zone or very early follicle center derivation. The immunophenotypes of MLCBCC (IgM+ or IgG/IgA+, MT1-, CALLA+) indicate a "true" follicle center derivation. The morphologic diversity of MLCBCC could not be related to specific immunophenotypes.