[The Place of Endorectal Ultrasonography in Diagnosis and Treatment of Villous Rectal Tumors]

Appropriate treatment of villous adenomas of the rectum remains a challenge, since accurate diagnosis can only be established after total removal of the lesion. The aim of the study was to assess the contribution of endorectal ultrasound (EUS) to diagnosis and treatment of these tumours. From 1989 to 1992, 22 patients with 24 villous adenomas of the rectum had preoperative EUS. Sixteen tumours were Cl (< 1/3 of the rectal 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 cases, 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 (invasive cancers) in 5 and 2 cases respectively. Patients had local excision of the tumours in 21 cases, and a radical rectal resection in 3. Accuracy of pathological sampling and EUS for diagnosis were evaluated, as well as the contribution of EUS to the treatment. Multiple biopsies achieved a 62% accuracy rate of diagnosis. Sensitivity in detecting invasive cancer was 71,5%. EUS reached a 92% accuracy rate ; sensitivity and specificity in detecting invasive cancers were 85% and 94% respectively. The initial therapeutic option was modified.in 6 patients as result of EUS stadification : undelayed surgery instead of iterative coagulations (n=1), radical instead of local resection (n=2) and local instead of rectal resection (n=3). It is concluded that EUS is useful in confirming diagnosis, providing additional data about infiltration depth of any suspected malignant transformation, and in contributing positively to the treatment in as many as 6 among 24 cases.