Fine needle aspiration cytology diagnosis, flow cytometry immunophenotyping and histology in clinically suspected lymphoproliferative disorder: a comparative study.

OBJECTIVE: To evaluate advantages and drawbacks of fine needle aspiration cytology (FNAC) with flow cytometry (FC) in our routine, using, whenever possible, histology as the gold standard. STUDY DESIGN: From November 2003 to April 2005, we studied, by FNAC and FC, 113 patients with a tentative clinical diagnosis of lymphoproliferative disorder. Excision was performed in 43 patients. RESULTS: Excluding the 7 cases in which FNAC/FC made the diagnosis of metastatic carcinoma, a conclusive diagnosis was obtained with FNAC/FC in 87.7% (93 of 106) of patients. Most of these (n = 48) corresponded to reactive processes. Histologic study of 8 cases confirmed FNAC/FC diagnosis of reactive process. Insufficient material was obtained in 8 (7.1%) patients, and discordance between FNAC and FC occurred in 5 (4.4%), leading to inconclusive diagnosis. There was concordance in benign and malignant diagnoses between FNAC/FC and histology in every case in which conclusive diagnosis of FNAC/FC was advanced. CONCLUSION: FNAC and FC together provide a reliable, definitive diagnosis in most cases, obviating, whenever a reactive process is found, unnecessary surgery or follow-up. Histology was useful in the few cases in which FNAC/FC could not reach conclusive diagnosis and in subclassification of specific lymphomas.