Two lymphoma cell lines of B-cell type were established from Japanese patients with diffuse small noncleaved cell lymphoma. Cytogenetic analysis revealed a 14q+ marker chromosome in both cell lines, and a t(8;14)(q24.1;q32.3) seemed most likely to have occurred. The chromosome 8 pair, however, had no abnormalities. Molecular analysis demonstrated c-myc amplification lacking gross rearrangement in one cell line and genetic rearrangement of c-myc at the first intron as well as aberrant sizes of c-myc mRNA in the other cell line. In the latter case, it is possible that a t(8;14)(q24.1;q32.3) was buried in an unrecognized complex translocation. A combination of cytogenetic and molecular studies to determine the precise nature of the 14q32 translocation is discussed.