A new cell line, designated UCH1, was established from a patient with splenic marginal zone lymphoma (SMZL). UCH1 cells feature a mature B-cell phenotype, characterized by surface IgM +, kappa+, CD5-, CD10-, CD19+ and CD20+. The BCL2 and BCL6 genes retained their germ-line configurations and overexpression of cyclin D1 was not detected. UCH1 cells carry numerical and structural aberrations in chromosome 3, but these were too complex to be analyzed with the conventional G-banding method. Spectral karyotyping (SKY) and fluorescence in situ hybridization analysis clearly demonstrated the presence of a balanced translocation between chromosomes 8 and 14 [t(8;14)(q24;q32)] in the complex aberrations involving chromosome 3. The results of Southern blot analysis supported this finding by showing rearrangement of the c-myc gene in UCH1 cells. SKY analysis also identified a translocation involving chromosome band 18q21, to which BCL2 and MALT1 genes were assigned, suggesting their implication in the development or progression of SMZL.