Mediastinal lymph node staging with transesophageal echography in cancer of the lung

Transesophageal echography (TEE) was used prospectively to study mediastinal lymph node enlargement in 23 patients with cancer of the lung. The findings were validated blindly by comparison with computed tomography (CT, n = 23) and pathological N classification after curative surgery (n = 9). Lymph nodes larger than 1 cm were defined as pathologically enlarged. In the upper mediastinum, 22% (8 vs 36), in the lower mediastinum including the subaortic region 112% (37 vs 33) and in the hilar region 67% (6 vs 9) of enlarged lymph nodes diagnosed by CT were detected by TEE. A pathological study in 9 patients demonstrated true positive findings in 2 vs 1, true negatives in 4 vs 5, false positives in 3 vs 2 and false negatives in 0 vs 1 comparing TEE with CT. From these preliminary data, we conclude that TEE, although still experimental, is equal or superior to CT in detecting enlarged nodes in the lower mediastinum, specifically in the aortopulmonary window but clearly inferior in the upper mediastinum and the hilar region. Additional information on central tumors and infiltration of the heart or great vessels can be clarified. In addition, data on hemodynamics and cardiac status can be obtained. TEE seems to be a promising tool in the preoperative staging of lung cancer.