Endosonographic features predictive of lymph node metastasis.

Endosonographic features that are thought to characterize lymph node metastasis were evaluated in 100 patients with esophageal carcinoma. Subjects underwent preoperative endoscopic ultrasonography to assess depth of tumor invasion (T stage) and lymph node metastasis (N stage). Endosonographically imaged lymph nodes were evaluated according to the following parameters: size, shape, border demarcation, and central echo pattern. Sensitivity and specificity of endosonography in detecting lymph node metastasis were 89.1% and 91.7%, respectively, when stringent criteria were used. When lymph nodes were imaged endosonographically, regardless of the specific features, the likelihood of N1 disease, was 86%, whereas when no lymph nodes were imaged, the chance of N0 disease was 79%. Endosonographic features predictive of malignancy in increasing order of importance were echo-poor (hypoechoic) structure, sharply demarcated borders, rounded contour, and size greater than 10 mm. Collectively, the EUS features produced an additive effect with respect to accuracy in the prediction of malignant lymph node involvement; malignancy could be predicted with 100% accuracy when all four features were present. These results demonstrate that a careful and systematic approach to the endosonographic assessment of lymph node metastasis can improve staging accuracy.