The accuracy of combined cytopathologic and flow cytometric analysis of fine-needle aspirates of lymph nodes

We studied flow cytometry in 156 fine-needle aspirations (FNAs) of lymph no des performed between June 1993 and September 1998. Information from flow c ytometry was combined with cytomorphologic evaluation, and the diagnosis de termined by using combined modalities was compared with tissue biopsy resul ts or clinical follow-up. In 74 cases, a combined cytopathologic-flow cytom etric diagnosis of lymphoma was made; histologic material was available for 52 patients; in no case was a benign process found. The lymphoma grade ass igned agreed with histopathologic findings in 45 of 48 cases with a specifi c cytologic diagnosis. Treatment was initiated on the basis of the FNA alon e for 17 of 52 patients with a history of lymphoma and in 22 additional pat ients with no follow-up biopsy. Among 71 cases in which the diagnosis using both modalities was benign, the only false-negative was 1 case of Hodgkin disease of the 156 cases, II were considered atypical or suggestive of lymp homa; biopsies from 8 of 10 patients revealed lymphoma. A combination of fl ow cytometry and cytomorphology of cells obtained by FNA of lymph nodes can distinguish between benign and malignant lymphoid infiltrates and support a diagnosis of lymphoma that permits definitive therapy in most cases.