Detection of B cell lymphoma involvement in T cell-rich serous fluid by immunoglobulin gene rearrangement: a report of 2 cases

BACKGROUND: Cytology, flow cytometry and gene rearrangement studies are methods to detect lymphoma involvement of body fluid. The cytology of the effusion is equivocal for lymphoma involvement. CASES: We report 2 cases of diffuse large B cell lymphoma with massive lymphocyte predominant serous fluid, ascites in one case and pleural effusion in the other. Immunophenotypic analysis by flow cytometry showed that lymphoid cells express only T cell markers. Lymphoma involvement of effusion was confirmed by immunoglobulin gene rearrangement detected by polymerase chain reaction. CONCLUSION: Our case demonstrated the value of gene rearrangement study in establishing diagnosis of equivocal cases.