The use of rectal ultrasound for the correct diagnosis and treatment of rectal villous tumors

BACKGROUND: One of the difficulties associated with surgery for rectal vill ous tumors (RVT) is the finding of invasive adenocarcinoma after transanal excision (TAE) and the possible need for more radical procedures or adjuvan t therapy. Improved preoperative evaluation may eliminate this dilemma. The aim of our study was to evaluate the role of transrectal ultrasound (TRUS) in establishing the correct diagnosis of RVT. METHODS: All patients with biopsy proven RVT, who were referred for TAE, un derwent preoperative TRUS in addition to the routine evaluation. If invasio n beyond the submucosa was suspected by TRUS, multiple biopsies were taken before any surgical intervention in order to exclude invasive cancer. If no invasion was noted, biopsies were avoided and a TAE was performed. The fin al pathology results were compared with both the preoperative diagnosis and TRUS results. RESULTS: Thirty-five patients (19 female, 16 male; mean age 67.5 years, ran ge 36 to 88) were studied. The mean distance of the distal extent of the le sion above the anal verge was 5.8 cm (1.5 to 6), In 27 patients, the tumor was limited to the submucosa (uT0, uT1) on TRUS and, therefore, TAE was per formed. In 26 of 27 patients (96%), pathology examination confirmed the pre sence of RVT without evidence of malignancy. One patient was found to have invasion of the muscularis propria and required postoperative radiation the rapy. In 8 patients (23%), TRUS showed extension beyond the submucosa; 3 of these patients had uT2 lesions, 4 had uT3 tumors, and 1 had perirectal nod es. These 8 patients underwent repeated biopsies with the finding of invasi ve adenocarcinoma in 7, Two patients underwent abdominoperineal resection, 3 had a low anterior resection, and 3 had a TAE. Final pathology confirmed the preoperative diagnosis of invasive adenocarcinoma in 7 patients. In the 1 patient with a uT2 lesion and negative biopsies, the final diagnosis was RVT with no evidence of malignancy. CONCLUSIONS: Preoperative TRUS provides an accurate diagnosis of RVT. In co njunction with TRUS-directed biopsies, directed management of these tumors could be achieved, Am J Surg. 2000;179:261-265. (C) 2000 by Excerpta Medica , Inc.