Combining morphology and flow cytometric immunophenotyping to evaluate bone marrow specimens for B-cell malignant neoplasms

For this study, 188 bone marrow core biopsy specimens and aspirates analyzed morphologically and by flow cytometric immunophenotyping (FCI) in patients with a previous or new diagnosis of B-cell non-Hodgkin's lymphoma or mature B-cell leukemia were retrospectively reviewed to evaluate patterns of involvement and the usefulness of FCI. The morphologic and FCI results were categorized as follows: positive by morphologic examination and by FCI (39.9%); negative by morphologic examination and by FCI (41.5%); positive by morphologic examination and negative by FCI (11.7%); negative by morphologic examination and positive by FCI (2.6%); suggestive of malignant neoplasm by morphologic examination and positive by FCI (2.1%); and suggestive of malignant neoplasm by morphologic examination and negative by FCI (2.1%). Thus, in 81.4% of cases the morphologic and FCI findings were completely concordant, in 11.7% of cases, the morphologic examination alone detected involvement, and in 4.7% of cases, the FCI data detected involvement in a morphologically negative or "suggestive" bone marrow core. Combining these modalities is essential to evaluate bone marrow specimens for involvement by B-cell non-Hodgkin's lymphoma or B-cell leukemia.