Role of fine-needle aspirate immunophenotyping by flow cytometry in rapid diagnosis of lymphoproliferative disorders.

Immunophenotyping is an essential component in the diagnostic work-up of lymphoproliferative disorders (LPD). As compared to immunohistochemistry, flow cytometric immunophenotyping (FCMI) is rapid, quantitative and a more objective technique. This study was designed to evaluate the utility of FCMI on fine needle aspirates (FNA) in rapid diagnosis of LPD in routine clinical practice. FNA from 31 consecutive cases clinically suggestive of LPD were subjected to FCMI. Representative material for FCMI was obtained in 28 (90%) cases and a definite diagnosis established in 27 cases. Histopathogical correlation was available in 22 cases and concordance with FCMI results was observed in 19 (86.4%) cases. FCMI analysis was inconclusive in 4 cases. The results of FCMI were available the same day and were crucial for therapeutic purpose in 3 patients with superior vena cava syndrome. FCMI combined with cytological examination of aspirate smears permits rapid diagnosis with high level of accuracy resulting in efficient treatment planning for critically ill patients and those from far-off rural areas.