T-cell-rich B-cell lymphoma: fine-needle aspiration cytology and immunocytochemistry

Cytomorphologic and immunocytochemical characteristics of FNA aspirates from 5 patients with T-cell-rich B-cell lymphoma are described. The aspirates were dominated (over 90%) by small mature lymphocytes, but there was a sparse admixture of large, immature lymphoid cells, some of which mimicked Hodgkin's or Reed Sternberg's cells. The cytologic picture of 3 cases was similar to that of Hodgkin's disease of lymphocytic predominance. Two cases presented, in addition to the components described above, fragments of small vessels and epithelioid cells, which raised the possibility of true T-cell lymphoma. Immunocytochemical analysis of cytospin preparations showed that the mature small lymphocytes were of T-phenotype, while the large cells were of B-phenotype. Light-chain restriction was demonstrated in all cases, and monoclonality for kappa and lambda was shown in 4 cases and 1 case, respectively. Three cases had a previous histological diagnosis of Hodgkin's disease, which was revised to T-cell-rich B-cell lymphoma as a consequence of the cytologic and immunologic findings in aspirates from recurrent/remaining lymphoma manifestations. It can thus be concluded that immunocytochemistry in conjunction with cytomorphology on fine-needle aspirates will allow a conclusive diagnosis of T-cell-rich B-cell lymphoma and its differentiation from Hodgkin's disease and T-cell lymphomas. This distinction, from a prognostic and therapeutic standpoint, is of utmost importance.