Rectal endosonography in the evaluation of stenotic rectal tumors.

Preoperative evaluation of stenotic rectal tumors is important since they often involve adjacent organs and thus may require additional therapy. Previous reports on endosonographic staging have excluded stenotic tumors because they could not be fully visualized with the available equipment. In this study, we have evaluated the role of endosonography in staging stenotic rectal tumors, with special attention to the use of forward-looking endoprobes. Preoperative staging was performed in 28 patients with stenotic rectal tumors. Tumor extension was evaluated according to the TNM classification, and the results were compared with surgical and histopathologic findings. Endosonography accurately assessed tumor extension in two T2 tumors, 14 T3 tumors, and seven T4 tumors. Three T2 tumors were overstaged, and two T4 tumors were staged as T3. The accuracy was 82 percent. Twenty-two tumors were subject to histopathologic evaluation of lymph nodes. Lymph nodes larger than 1 cm had been seen by endosonography in eight patients, five of whom had nodal metastases. Lymph nodes smaller than 1 cm or no lymph nodes were found in 14 patients, four of whom had nodal metastases. In conclusion, full sonographic visualization of stenotic rectal tumors and thus evaluation of tumor extension can be achieved by using forward-looking endoprobes.