Use of endoscopic ultrasonography for the diagnosis of colorectal tumors.

Ultrasonographic evaluation of colorectal diseases has been realized by the development of echocolonoscopes. Endoscopic ultrasonography was performed in 90 cases of colorectal tumor, and the diagnostic yields were assessed; the cases included 72 with cancer, 13 with polyp, and 5 with submucosal tumor. With respect to cancer extent, EUS correctly estimated the depth of cancer invasion in 84.9% of 53 cases in which the lesion was appropriately visualized. Paraintestinal lymph node metastasis was detected in 38.1%. EUS was not so successful in the evaluation of polyps, since the histological types could not be differentiated, nor could the focus of cancer in adenoma be demonstrated. EUS was effective in the differential diagnosis of submucosal tumors, since the ultrasonographic features varied by histological types.