Immunophenotyping by flow cytometry of fine needle aspirates in the diagnosis of lymphoproliferative disorders: A retrospective study.

In order to determine the value of flow cytometric (FCM) immunophenotyping of fine-needle aspirates (FNA) in the diagnosis and classification of lymphoproliferative diseases, 61 tissue samples were studied and compared with the cytologic/histological results. In vivo and ex vivo FNA biopsy yielded the material for FCM, which comprised an extensive number of lymphoid cell markers. In all but three cases sufficient cells were collected. Overall, malignancy was diagnosed in 33 cases from a total of 47 (70.2%), and in the remaining cases malignancy was not detected. Eleven cases were correctly diagnosed as reactive processes (11/11). There were no false positive cases of malignancy, as diagnosed by FCM-FNA. The best accuracy was achieved in the low-grade B-cell lymphomas and lymphoblastic lymphoma/leukemia. We conclude that in a significant number of cases, FCM-FNA permits the separation between lymphoid malignancies and reactive processes without false positive results. It was found to be particularly useful in the differential diagnosis of mantle-cell and small-lymphocytic lymphoma and in the identification of lymphoblastic lymphoma/leukemia.