B-CELL MALIGNANCY AFTER LOW-GRADE T-CELL LYMPHOMA

Background. Low grade, small lymphocytic, non-Hodgkin's lymphoma, was diagnosed in a 38-year-old woman. Thirty months after the initial diag nosis was made, a population of lymphoid cells with pathologic morphol ogy was found in the patient's peripheral blood (PB). Cell phenotyping was performed and monoclonality was analyzed in cells obtained from a removed lymph node (LN) and the PB of the patient. Methods. The cell phenotype was examined with immunofluorescence techniques using antibo dies against SIg and monoclonal antibodies against CD1, CD3, CD4, CD5, CD8, CD19, and the kappa, and lambda light chains. Gene rearrangement analysis for monoclonality determination was performed with restricte d DNA (EcoRI, HindIII and BamHI) hybridized with either P-32-labeled T -cell receptor DNA probe (TcR-beta) or immunoglobulin-heavy chain prob e (TH). Results. With regard to the cell population of the removed LN, cell phenotyping showed the predominance of CD4+ T-cells over a polyc lonal B-cell population. Gene rearrangement analysis proved the monocl onal nature of the T-cells and the polyclonal nature of the B-cells. A s to the PB, gene rearrangement and cell phenotyping of the lymphocyte s showed the predominance of monoclonal kappa type B-cells over polycl onal T-cells. Conclusions. The data obtained suggest two unrelated lym phoproliferative diseases in this patient, expressed as monoclonal T-c ell population in LN and as monoclonal B-cell population in PB.