Preoperative TNM classification of esophageal carcinoma by endosonography.

Endosonography was performed preoperatively in 111 patients with an esophageal carcinoma. The results were correlated with the histology of resected specimens employing the new (1987) TNM classification. Endosonography was accurate in assessing the depth of tumor infiltration (overall accuracy: 89%). Early carcinomas could be distinguished from advanced cancer. Extensive stenosis preventing the passage of the instrument was a limiting factor prior to the availability of a small-caliber catheter echoprobe (25% of cases). Endosonography was helpful for diagnosing lymph node metastasis, but was less accurate in defining non-metastatic enlarged lymph nodes (accuracy: 81%, sensitivity 95% and specificity 50%). The incidence of lymph node metastasis increased with the progression of tumor infiltration. Endosonography was also less accurate for diagnosing liver metastases and peritoneal dissemination because of the low depth of penetration of ultrasound. Technical improvements such as a reduction in the diameter of the instrument will further enhance the accuracy of endosonography. Moreover, ES-guided cytology may become helpful for confirming the ES diagnosis of lymph node metastasis.