Endoscopic ultrasound-guided fine needle aspiration is superior to lymph node echofeatures: a prospective evaluation of mediastinal and peri-intestinal lymphadenopathy.

BACKGROUND AND OBJECTIVE: The additional diagnostic value of endoscopic ultrasound-fine needle aspiration (EUS-FNA) over lymph node (LN) echofeatures alone in evaluating lymphadenopathy is unknown. The objectives of this study are (1) to prospectively evaluate the utility of EUS-FNA in evaluating mediastinal or peri-intestinal lymphadenopathy and to compare its yield to that of echofeatures alone and (2) to determine clinical and endosonographic features predictive of malignant involvement of LNs.

METHODS: All consecutive patients who underwent EUS-FNA of a LN over a 22-month period were prospectively evaluated. Reference standard for final diagnosis included: surgery (n = 76), long-term clinical and/or imaging follow-up (n = 74), or death from disease (n = 26).

RESULTS: One hundred and eighty-three EUS-FNAs of LNs were performed in 137 patients with no major complications. Locations of the biopsied LNs included 31% subcarinal, 21% celiac, 21% peripancreatic, 13% periesophageal, 4.4% aortopulmonary window, 3.2% perigastric, and 3.3% perirectal. Mean LN size was 20.5 mm (SD +/- 11.1) x 13.2 mm (SD +/- 7.97). The mean number of EUS-FNA passes was three (range 1-7). The sensitivity, specificity, PPV, and NPV of EUS-FNA of LNs were 98.3%, 100%, 100%, and 98.4%, respectively. EUS-FNA was more accurate compared to LN echofeatures alone (99.4%vs 75.4%, p < 0.001). Mediastinal LNs were 2.77 times less likely to be malignant as compared to other LN locations. In multivariable analysis, the number of LN echofeatures, site of LN, and patient's age were associated with malignant involvement (p= 0.001).

CONCLUSIONS: EUS-FNA is superior to LN echofeatures in evaluating lymphadenopathy. Endosonographic LN features alone are particularly unreliable in the mediastinum, necessitating tissue confirmation. EUS-FNA can safely, reliably, and accurately sample mediastinal and peri-intestinal LNs obviating the need for more invasive testing or surgical intervention.