Randomized controlled trial of EUS-guided fine needle aspiration techniques for the detection of malignant lymphadenopathy

Background. EUS-guided fine needle aspiration (EUS-FNA) is a highly accurat e method of detecting malignant lymphadenopathy. The optimal methods for pe rforming EUS-FNA to maximize sensitivity and to minimize the number of need le passes necessary are unknown. This is a report of the results of a prosp ective randomized controlled trial to determine the effect of suction, the site of FNA (edge or center of lymph node), and the method of preparation o f cytologic specimens on accuracy, number of needle passes needed, and spec imen quality. Methods: Consecutive patients with lymphadenopathy detected by EUS underwen t FNA. Each lymph node was sampled with or without suction and from the edg e or center in a 2 x 2 factorial design. The samples were expressed onto sl ides for cytology, and the residual material in the needle was analyzed by the cytospin-cel I block technique. Each aspirate was individually characte rized for a diagnosis of malignancy, cellularity, and bloodiness. Results: Forty-three patients with a total of 46 lymph nodes were evaluated . The final lymph node diagnosis was benign in 22 (48%), "suspicious for ma lignancy" in 6 (13%), and malignant in 18 (39%). The use of suction was ass ociated with an increase in the cellularity of the specimen, but did not im prove the likelihood of obtaining a correct diagnosis (OR 1.52: 95% Cl [0.8 1, 2.85]). Samples obtained with suction were of worse quality because of e xcessive bloodiness (OR 4.7: 95% Cl [1.99,11.24]). Aspiration from the edge of the lymph node (compared with the center) did not increase the likeliho od of a correct diagnosis (OR 1.16: 95% Cl [0.42, 3.21]). For 78% of malign ant lymph nodes, the correct diagnosis was obtained on the first needle pas s and for 100% by the third pass. Cytospin-celiblock methods did not add an y additional diagnostic information compared with direct smear cytology. Conclusions: The traditional method of applying suction during EUS-FNA does not improve diagnostic accuracy and worsens specimen bloodiness compared w ith FNA without suction. The site of FNA within the lymph node does not aff ect accuracy. When EUS-FNA is necessary, our recommendation is up to 3 FNAs without suction from the most convenient and safe location within abnormal -appearing lymph nodes.