Preoperative detection of distal intramural spread of lower rectal carcinoma using transrectal ultrasonography

PURPOSE: Usefulness of transrectal ultrasonography (TRUS) for detecting distal intramural spread of rectal carcinoma was investigated. METHODS: Thirty-seven patients with advanced rectal carcinoma, who had not received preoperative adjuvant therapy, underwent TRUS before surgery. Dis tal intramural spread was evaluated by TRUS and by pathologic examination of resected specimens. RESULTS: Distal intramural spread was found in 7 of 37 patients (19 percent) by pathologic examination. Presence or absence of distal intramural spread was correctly diagnosed by TRUS in 86 percent of the 37 patients. Misdiagnosis by TRUS mainly occurred when distal intramural spread was 5 mm. Tumor penetration of muscularis propria, lymph node involvement, and a higher histologic grade of malignancy showed a significant relationship with the presence of distal intramural spread. CONCLUSION: TRUS was useful for detecting distal intramural spread >5 mm in patients with lower rectal carcinoma and may be helpful for selecting appropriate surgery.