Ex vivo fine-needle aspiration cytology and flow cytometric phenotyping in the diagnosis of lymphoproliferative disorders: a proposed algorithm for maximum resource utilization.

Surface marker characterization of lymphoproliferative disorders is an essential component in the diagnostic work-up of these lesions. Immunohistochemical surface marker analysis (SMA) is somewhat costly, fixation-dependent, and difficult to objectively quantitate. Two-color flow cytometric (TCFCM) SMA allows for more quantitative dual marker analysis of a wide range of surface antigens, and is less expensive. Ex vivo fine-needle aspiration (xvFNA) has been reliably used for FCM DNA analysis. The procedure has also been used to harvest tumor cells for xenotransplantation. In this study, we attempted to test the reliability of material obtained by xvFNA for SMA. We also designed an algorithm initiated by cytological assessment of the xvFNA smears in order to tailor the panel of antibodies required for TCFCM SMA of the aspirates. We performed 20 xvFNAs on freshly resected specimens from 19 patients with suspected lymphoproliferative disorders. The specimens included 12 lymph node biopsies, seven splenectomies, and one breast biopsy. There were 10 male and nine female patients with a median age of 58 yr. The aspirate cell suspensions were examined by FCM within 24 hr of harvesting. The number of markers used ranged from four to 14 with an average of eight. The diagnoses included non-Hodgkin's lymphoma (n = 5), lymphocytic leukemia (n = 5), reactive lymphoid hyperplasia (n = 8), and Hodgkin's disease (n = 1). Combining cytological assessment of the xvFNA smears and TCFCM SMA, the diagnosis was reached prior to histopathologic examination in 17 cases (90%). The two remaining cases showed a reactive pattern on cytology and a polyclonal FCM SMA profile, and the diagnosis of sarcoidosis and toxoplasmosis was made on histological examination. Our study suggests that xvFNA provides adequate material for TCFCM SMA. An algorithm combining xvFNA cytology, FCM SMA, and histological examination is appropriate for the diagnosis of lymphoproliferative disorders in most instances with maximal resource utilization and minimal expense.