Role of endoscopic ultrasound-guided fine-needle aspiration with flow cytometry to diagnose lymphoma: a single center experience.

BACKGROUND AND AIM: The use of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) +/- flow cytometry (FC) for the diagnosis of suspected lymphoma remains controversial. We report our experience and diagnostic yield for EUS +/- FC for suspected lymphoma.

METHODS: Databases were queried for those who underwent EUS-FNA +/- FC for suspected lymphoma. Hospital charts were reviewed to confirm the final cytological diagnosis, follow up and FC results if obtained. The final diagnosis was confirmed by the results of EUS-FNA +/- FC, other biopsy and/or follow up.

RESULTS: In total, 54 patients underwent EUS-FNA of 72 lesions. The final diagnosis of lymphoma was made in 38 of the 54 (70%) patients, and 33 of the 54 (61%) patients relied on EUS-FNA. Cytopathology in 41 patients using EUS-FNA + FC showed lymphoma in 24 patients, atypical lymphoid cells in six and reactive lymph node in 11. In 9 of the 24 with lymphoma by EUS + FC, the diagnosis was confirmed by another diagnostic modality, like surgery, bone marrow biopsy and computed tomography-guided biopsy. Of the six with atypical lymphoid cells, additional diagnostic methods confirmed lymphoma in three. The remaining 13 of the 54 patients underwent EUS-FNA without FC due to insufficient sample (n = 5) or operator choice (n = 8). Cytopathology in these 13 patients without FC showed lymphoma (9), atypical lymphoid cells (3) and reactive node (1). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS-FNA for lymphoma in all 54 patients ranged from 80% to 87%, 92% to 93%, 97%, 60% to 75% and 83% to 89%, respectively.

CONCLUSIONS: EUS-FNA is sensitive and specific for the diagnosis of suspected lymphoma. Confirmatory or further testing should be performed when EUS-FNA with or without FC is indeterminate and or non-diagnostic.