THE PLACE OF ENDORECTAL ULTRASONOGRAPHY I N DIAGNOSIS AND TREATMENT OF VILLOUS RECTAL TUMORS

Appropriate treatment of villous adenomas of the rectum remains a chal lenge, since accurate diagnosis can only be established after total re moval of the lesion. The aim of the study was to assess the contributi on of endorectal ultrasound (EUS) to diagnosis and treatment of these tumours. From 1989 to 1992, 22 patients with 24 villous adenomas of th e rectum had preoperative EUS. Sixteen tumours were Cl (< 1/3 of the r ectal circumference), 6 were C2 (between 1/3 and 2/3), and 2 were C3 ( > 2/3). Multiple biopsies showed slight or moderate dysplasia in 12 ca ses, severe dysplasia or islets of invasive cancer in 12 cases. Depth of tumoural invasion could not be established. Tumours were staged by EUS as uT1 (no malignant infiltration) in 17 cases, uT2 and uT3 (invas ive cancers) in 5 and 2 cases respectively. Patients had local excisio n of the tumours in 21 cases, and a radical rectal resection in 3. Acc uracy of pathological sampling and EUS for diagnosis were evaluated, a s well as the contribution of EUS to the treatment. Multiple biopsies achieved a 62% accuracy rate of diagnosis. Sensitivity in detecting in vasive cancer was 71,5%. EUS reached a 92% accuracy rate ; sensitivity and specificity in detecting invasive cancers were 85% and 94% respec tively. The initial therapeutic option was modified.in 6 patients as r esult of EUS stadification : undelayed surgery instead of iterative co agulations (n=1), radical instead of local resection (n=2) and local i nstead of rectal resection (n=3). It is concluded that EUS is useful i n confirming diagnosis, providing additional data about infiltration d epth of any suspected malignant transformation, and in contributing po sitively to the treatment in as many as 6 among 24 cases.