[Evaluation of lymph nodes metastasis in lung cancer by endoscopic ultrasonography]

The value of endoscopic ultrasonography (EUS) in diagnosing lymph node metastasis in lung cancer was investigated. The endoscope is composed of an ultrasonic linear array transducer (7.5 MHz). EUS findings of 101 lymph nodes in 25 patients with non-small cell lung cancer who underwent thoracotomy and mediastinal lymph node dissection were reviewed. EUS data on the size, shape, boundary and internal echo of the lymph nodes was correlated with the histological findings. From the characteristics of their shape, boundary and internal echo, hyperechoic lymph nodes with unclear boundaries were histologically metastasis negative and lobulative lymph nodes were metastasis positive. Using the criteria of a long-plus-short diameter > or = 17 mm and a ratio of long to short diameter < 1.8, or a lobulative shape, rates of 91% sensitivity, 91% specificity and 91% accuracy were obtained. EUS combined with CT increases the accuracy of preoperative diagnosis of lymph node metastasis.