Immunophenotyping of mature B-cell non Hodgkin lymphoma involving bone marrow and peripheral blood: critical analysis and insights gained at a tertiary care cancer hospital.

We evaluated the diagnostic utility of flow cytometry immunophenotyping in bone marrow aspirates and peripheral blood, in the assessment of mature B-cell non-Hodgkin lymphoma (MBNHL). We analyzed 356 cases of MBNHL received for immunophenotyping over a 4 year period. All cases were reviewed, correlated with biopsy specimen (lymph node and splenectomy). Discrepant cases were re-evaluated. Common subtypes included chronic lymphocytic leukemia (CLL) (243 cases, 68.5%), follicular lymphoma (30 cases, 8.5%), mantle cell lymphoma (20 cases, 5.5%), splenic marginal zone lymphoma (18 cases, 5%), hairy cell leukemia (18 cases, 5%). CD5+/CD23+ had a high positive predictive value (PPV) for diagnosing CLL whereas CD5+/CD23- had a high negative predictive value (NPV) for diagnosing mantle-cell lymphoma (MCL). Limited panel of 9 antibodies mainly CD19, CD5, CD23, CD10, FMC7, kappa, lambda, CD3 and CD20 help diagnose more than 92% of cases of MBNHL. Minimal diagnostic panels become important in countries with limited resources.