Background: EUS-guided FNA is the most accurate method of confirming loco-regional malignant lymphadenopathy. The additional yield of FNA beyond endosonographic characteristic is unknown. Aims: 1) To determine if the detection of a CLN by EUS, independent of FNA, indicates malignant involvement. 2) To evaluate the accuracy of EUS in detecting CLN metastasis. Methods:We reviewed all cases of esophageal cancer that underwent EUS at our institution from 1/26/94 to 11/1/99. All staging was performed with a radial scanning echoendoscope (UM-20 or UM-130). FNA was performed of all accessible CLN with a linear scanning echoendoscope (UC-30 P, UCT-30, UM-30P). Patients were included in this study if they underwent surgery (n= 59), or if they had FNA of a celiac LN (n=44). The accuracy of EUS compared to cytology or histology was subsequently determined. Results: 103 patients with esophageal cancer met inclusion criteria. Seventy eight percent were male and 76% were Caucasian. Fifty five percent had adenocarcinoma of the esophagus and 79% of the tumors were confined to the distal esophagus or GE junction. Twenty five percent underwent dilation to 45 Fr to complete the examination. No complications were encountered. EUS imaging identified 48 true positive patients with CLN, 6 false positive, 14 false negative and 35 true negative. Therefore, the sensitivity of EUS in detecting CLN was 77% (95% CI, 67-88), the specificity 85% (95% CI, 75-96), the negative predictive value 71%, and the positive predictive value 89%. The overall accuracy of EUS was 81%. EUS FNA confirmed the nature of a CLN in 88% of the cases. Seventy eight percent (21/27) of EUS-detected CLN ≤ 1cm were malignant while 100% (25/25) of EUS-detected CLN >1 cm were malignant (p=0.02). Conclusions: Approximately ninety percent of CLN detected by EUS in patients with esophageal cancer are ultimately proven to be malignant. Since cytological proof of malignant involvement is critical in clinical decision making, all visible CLN should undergo FNA. IF a CLN (>1 cm) is imaged by EUS and FNA is not technically feasible, this study suggests that the patient should be considered to have CLN malignant involvement and should be managed accordingly. Background: EUS-guided FNA is the most accurate method of confirming loco-regional malignant lymphadenopathy. The additional yield of FNA beyond endosonographic characteristic is unknown. Aims: 1) To determine if the detection of a CLN by EUS, independent of FNA, indicates malignant involvement. 2) To evaluate the accuracy of EUS in detecting CLN metastasis. Methods:We reviewed all cases of esophageal cancer that underwent EUS at our institution from 1/26/94 to 11/1/99. All staging was performed with a radial scanning echoendoscope (UM-20 or UM-130). FNA was performed of all accessible CLN with a linear scanning echoendoscope (UC-30 P, UCT-30, UM-30P). Patients were included in this study if they underwent surgery (n= 59), or if they had FNA of a celiac LN (n=44). The accuracy of EUS compared to cytology or histology was subsequently determined. Results: 103 patients with esophageal cancer met inclusion criteria. Seventy eight percent were male and 76% were Caucasian. Fifty five percent had adenocarcinoma of the esophagus and 79% of the tumors were confined to the distal esophagus or GE junction. Twenty five percent underwent dilation to 45 Fr to complete the examination. No complications were encountered. EUS imaging identified 48 true positive patients with CLN, 6 false positive, 14 false negative and 35 true negative. Therefore, the sensitivity of EUS in detecting CLN was 77% (95% CI, 67-88), the specificity 85% (95% CI, 75-96), the negative predictive value 71%, and the positive predictive value 89%. The overall accuracy of EUS was 81%. EUS FNA confirmed the nature of a CLN in 88% of the cases. Seventy eight percent (21/27) of EUS-detected CLN ≤ 1cm were malignant while 100% (25/25) of EUS-detected CLN >1 cm were malignant (p=0.02). Conclusions: Approximately ninety percent of CLN detected by EUS in patients with esophageal cancer are ultimately proven to be malignant. Since cytological proof of malignant involvement is critical in clinical decision making, all visible CLN should undergo FNA. IF a CLN (>1 cm) is imaged by EUS and FNA is not technically feasible, this study suggests that the patient should be considered to have CLN malignant involvement and should be managed accordingly.