[Study of mediastinal lymph nodes in lung cancer using transesophageal ultrasonography]

Evaluation of mediastinal lymph nodes in patients with lung cancer is fundamental for their treatment and prognosis. Chest computed tomography (CT) is presently the most utilized diagnostic modality. In recent years endoscopic ultrasound (EUS) is being employed for this purpose. We retrospectively compared the results of CT and EUS staging of 35 selected patients with postsurgical stage. A total of 175 lymph node sites were examined. Results CT vs EUS were as follows: specificity 92% vs 98%, sensitivity 88% vs 84%, positive predicted accuracy 80% vs 96%, negative predicted accuracy 95% vs 94%, overall accuracy 92% vs 95%. The region most accessible by EUS evaluation were the paraesophageal lymph nodes; the most difficult were the right superior mediastinal nodes which cannot be imaged for anatomic reasons. EUS not only allows one to arrive at correct diagnosis with less false positive results, but also permits evaluation of lymph nodes which are not enlarged. We think that EUS, in combination with CT, is an appropriate modality for staging of mediastinal lymph nodes in patients with lung cancer.