We report the cytogenetic results in three cases of B-cell non-Hodgkin's lymphomas with morphologic and immunophenotypic features compatible with a non-follicle center cell lymphoma. In all cases, a chromosome breakpoint at 14q32 and structural abnormalities of 1p were found. Increased copies of chromosome segment 12q and structural rearrangements of chromosome 6 were found in two cases. Translocation (14;18)(q32;q21) with rearrangement of bcl-2 was found in one case. These lymphomas have a perifollicular growth pattern and IgM+, IgD+, CD10-, and CD22+ immunophenotype features typical of non-follicle center cell lymphomas and probably belong to the follicle mantle lymphomas described recently. Little cytogenetic data about this group of lymphomas is available, possibly because in the Working Formulation for the Classification of Lymphomas they are not separated from follicle center cell lymphomas.