Flow cytometrical and genotypic analysis of primary non-Hodgkin's lymphoma of bone.

Primary malignant lymphoma of bone presents both diagnostic and therapeutic problems. No previous study has addressed the use of flow cytometry in the immunophenotypic evaluations of bone lymphomas. A 41-year-old Japanese female presented with a large lytic lesion in the right femur. Biopsies from the lesion were examined by light microscopy, immunohistochemistry, 3-color flow cytometry and Southern blotting. Microscopic examination showed a diffuse, noncleaved large cell lymphoma. The lymphoid cells were positive for mature B cell antigens and the phenotype was: CD5-, CD10-, CD19+, 20+, CD22+, IgG+, IgA-, IgM-, kappa-, lambda+, CD1-, CD2-, CD3-, CD4-, CD7-, CD8-. Southern blot analysis revealed rearranged bands on both heavy- and lambda light-chain genes, in contrast to germline configuration on T cell antigen receptor (beta, gamma and delta) genes. Flow cytometry, in conjunction with morphologic and other molecular techniques, can provide a rapid and accurate means of diagnosing primary lymphoma of bone. In addition, the capabilities of flow cytometry to assess cell properties/constituents can be utilized in detailed analysis of adhesion molecules and activation antigen which may lead to better prediction of the prognosis of this group of lymphomas, and may provide further important data for the therapeutic decision making process.