Comparison of endoscopic ultrasound (EUS) and EUS guided FNA with computed tomography (CT) for detection of mediastinal lymphadenopathy

Purpose: To compare the rate of detection of mediastinal lymphadenopathy by EUS and CT scan. Methods: Data on 56 consecutive mediastinal EUS exams was collected. These exams were most commonly performed for evaluating benign and malignant esophageal neoplasms, staging lung carcinoma, or evaluation of mediastinal adenopathy of unclear cause. The EUS exams were performed with a radial instrument at 7.5 and 12 MHz. Results: EUS examination was positive for mediastinal lymphadenopathy in 47 patients. In 14 of these patients the CT scan results were not obtainable as the patients were referred from a number of institutions within the State of Ohio. In the other 33 patients with positive mediastinal lymph nodes on EUS, only 8 (24%) had mediastinal lymphadenopathy by CT scan while 25 (76%) had a negative CT scan despite a positive EUS for mediastinal lymph nodes. Nine patients had no mediastinal adenopathy by EUS, and CT scan was negative in 7 of these while CT scan was not done or was not available in 2. There was no patient with a positive CT scan for mediastinal lymph nodes but with a negative EUS. Nine patients among these 56 cases (16%) after radial EUS underwent linear EUS guided FNA of mediastinal lymph nodes when it was felt that the information would affect clinical management. Five of 9 FNAs (56%) were positive for malignancy. In these 9 patients with mediastinal lymph nodes who underwent EUS guided FNA, only 4 patients (44%) had any mediastinal lymphadenopathy by CT scan. Conclusion: 1) The detection rate of mediastinal lymphadenopathy is significantly better by EUS when compared to CT scan. 2) Only 24% of patients with mediastinal lymph nodes by EUS may have mediastinal lymph nodes by CT. 3) EUS has the added advantage of performing EUS guided FNA of mediastinal lymph nodes when the cytopathology results are likely to alter clinical decisions. 4) Lymph nodes subjected to EUS guided FNA may not be even visible by CT scan.