Endosonography for Rectal Carcinoma: Preoperative TNM Staging Compared to Histology

Abstract

Transreccal endosonography was performed preoperatively in 58 patients with rectal carcinoma. The results of endosonography were compared to the histology of resected specimens according to the new (1987) TNM (tumour, nodes, metastases) classification. Endosonography was accurate in the staging of tumour categories except with T2 carcinomas because of concomitant peritoneal abscesses, inflammation or tissue changes after irradiation therapy. The overall accuracy of endosonography was 81 %. Overstaging occurred in 17% and understaging in 2%. The accuracy of endosonography for staging regional lymph nodes was 74%, sensitivity was 95% and specificity 61 %. Endosonography was not accurate in the staging of distant metastases due to the limited penetration depth of ultrasound used. In conclusion, endosonography will become the standard for staging rectal carcinoma.