Endoscopic ultrasonography in the diagnosis of esophageal carcinoma.

In selection for esophageal cancer treatment, it is necessary to evaluate the tumor stage. We have used endoscopic ultrasonography (EUS) for diagnosis of the depth of cancer invasion and the presence of lymph node metastasis since 1983. The EUS image of the normal esophageal wall showed 5 layers. In all, 222 cases of esophageal cancer were examined with EUS, and a radical operation was performed on 139. In 78 of those cases, the scope was passed beyond the cancer site, and total observation was achieved (56%). The extent of cancer invasion was correctly determined in these 78 cases (84%). Thoracic lymph nodes that could be detected by EUS were located in the posterior mediastinum and measured more than 3 mm in diameter. Diagnostic criteria for lymph node metastasis were designated as follows: (1) spherical shape, (2) a distinct border, and (3) heterogenous echo spots within the nodes. The above criteria yielded a sensitivity of 87%, a specificity of 90%, and an overall accuracy of 89% according to the histological examination of the removed lymph nodes.