Immunological and molecular studies in a case of follicular lymphoma with an extra chromosome 12 and t(2;8) translocation

Two sequential lymph node biopsies taken from a non-Hodgkin lymphoma patient revealed two karyotype abnormalities peculiar to B cell neoplasias: trisomy 12 and t(2;8)(p12;q24) translocation. The first was documented in all cells analyzed, while the second was present in 20% of the metaphases from the first biopsy and in 100% from the second. This suggests that the t(2;8) translocation arose as a secondary karyotypic change. In addition, although immunological characterization of the neoplastic cells disclosed a monoclonal B cell population that expressed immunoglobulin κ light chains, as usually found in Burkitt's lymphoma with t(2;8) translocation, Southern blot analysis provided evidence of rearrangement in only one κ chain allele.