Immunophenotypic analysis of peripheral blood and bone marrow in the staging of B-cell malignant lymphoma

This study evaluated the contributing roles of flow cytometric immunophenot yping of blood and bone marrow and immunohistochemical paraffin section sta ining of bone marrow biopsies in the staging of B-cell malignant lymphoma. Flow immunophenotyping was performed on a marrow specimen in 175 cases; a c orresponding blood specimen was also immunophenotyped in 135 of these cases . Morphologic marrow involvement by lymphoma was found in 59 cases; flow im munophenotyping identified 54 cases with a monoclonal B-cell process: morph ology-positive/flow-positive (n = 49), morphology-positive/flow-negative (n = 10). morphology-negative/flow-positive (n = 5), and morphology-negative/ flow-negative (n = 111). The 10 morphology-positive/flow-negative cases inc luded 5 follicular and 5 large-cell lymphomas with minimal marrow involveme nt. All 5 morphology-negative/flow-positive cases were from patients with l arge-cell lymphomas and bulky clinical disease. Because the blood contained the same B-cell clone in 2 of 2 morphology-negative/flow-positive cases st udied, blood contamination of marrow may account for these findings. Blood flow cytometric immunophenotyping studies were positive in 32 cases; 30 had marrow involvement by morphology and were from patients with follicular, m antle cell, lymphoplasmacytic, small lymphocytic, or marginal zone lymphoma s. From our results, we conclude that (1) bone marrow flow cytometric immun ophenotyping is not a cost-effective replacement for good morphologic evalu ation in lymphoma staging and that (2) a positive peripheral blood flow cyt ometric immunophenotyping study when performed in low-grade lymphomas corre lates with marrow involvement. (C) 1999 by The American Society of Hematolo gy.