Applicazioni della citometria a flusso in Patologia emo-linfoproliferativa.

OBJECTIVES: Flow cytometry (FC) has proven useful in the evaluation of non Hodgkin's lymphomas (NHL) on samples obtained by fine-needle cytology (FNC) (1-4). Objective of this study is to evaluate the application of FC and FNC to the diagnosis and sub-classification of NHL.METHODS: FC was used to analyze 307 FNCs of lymphoproliferative processes; the first pass was used to prepare a smear which was Diff-Quik stained and evaluated to select cases suitable for FC. The remaining material left in the hub of the needle and a second pass were flushed with PBS solution when FC was required. Clinical data and microscopic features were used to lay out the panel of antibodies to apply in each case. FC was performed using the following phycoerythrin, perdin chlorophyll protein and fluorescein isothiocyanate antibodies: CD3, CD4, CD8, CD2, CD3, CD7, CD5, CD10, CD19, κ and λ light chains, FMC7, CD23, CD38, CD56, bcl-2, CD13, HLA-DR and a three-color Becton Dickinson (San José, CA) FACS scan. When a defined diagnosis of NHL was performed, the combination of cytological features and different expression and co-expression of the antibodies were used to classify, when possible, the specific subtype. RESULTS: Combined FC and FNC provided a diagnosis of benign reactive hyperplasia (BRH) in 135 cases, primary NHL (pNHL) in 70 cases and NHL recurrence (rNHL) in 77 cases. Clinical control confirmed the diagnoses of rNHL, histological (44 cases) and clinical control (26 cases) confirmed the 70 primary NHL and BRH; 26 cases were lost to the follow-up. Inadequate cases were represented by scanty cellular FNC and/or extensive hemorrhagic or necrotic material. In 10 suspicious cases, microscopic features were suggestive of NHL but FC gave unsatisfactory results. Out of 115 cases diagnosed by FNC and FC as NHL, the evaluation of different expression and co-expression of the antibodies and the cytological features, suggested a specific subtype in 70 cases. All the others, with negative or equivocal phenotype, were diagnosed just as B-cell NHL not otherwise specifiable. All the FNC/FC diagnoses were confirmed by histology and clinical follow-up except for 24 cases lost to follow-up. CONCLUSIONS: FNC offers vital cells to FC suitable for a timely and accurate diagnosis and sub-classifiction of NHL; in the near future histological evaluation will probably no longer be necessary for the all the diagnoses and follow-up of NHL processes avoiding useless and expensive surgical biopsies