Endosonographic TNM staging of extrahepatic bile duct cancer: comparison with pathological staging.

Endosonography was performed preoperatively in 33 patients with common bile duct carcinoma and in 43 patients with carcinoma of the common hepatic duct and its bifurcation. The results were correlated with the histology of resected specimens according to the new (1987) TNM (tumor, node, metastasis) classification. Endosonography was accurate in the evaluation of the depth of tumor infiltration. Overall accuracy for common bile duct carcinoma and common hepatic duct carcinoma was 82.8% and 85%, respectively. Endosonography was helpful in diagnosing regional lymph node metastases but not accurate in diagnosing nonmetastatic lymph nodes. With common bile duct carcinoma, the incidence of lymph node metastasis increased with progressive depth of tumor infiltration. No such correlation was found in common hepatic duct carcinomas. In the staging of distant metastasis, this technique was limited by the low-penetration depth of ultrasonography. Thus, additional transcutaneous ultrasonography or computed tomography was necessary for complete staging. The routine use of the biopsy channel for endosonographically guided aspiration puncture will further enhance the diagnostic value of endosonography in the future.