Colorectal villous tumors - Accuracy of the preoperative biopsies

This study was undertaken to assess the reliability of the endoscopic biops ies in the evaluation of colorectal villous tumors (CRVT). Ln 163 consecuti ve patients referred for surgical treatment of CRVT, preoperative evaluatio n had been routinely done by colonoscopy and multiple biopsies. Tumors were classified in 3 groups:low grade tumors, high grade tumors and adenocarcin omas. Infiltration in depth was staged on the postoperative specimens accor ding to the Dukes-Astler-Coller's classification. All the tumors were compl etely resected by surgery and definitive pathological diagnosis was establi shed, An exact correlation between the pre- and postoperative staging was o bserved in 48% of the cases. Accuracy averaged 54% in the group-by-group co mparison, with an overstaging rate of 6.7%, and an understaging rate of 39% . The incidence of adenocarcinomas was 22% in the group with clearly benign preoperative biopsies and 50% in the other cases. There were significantly more B2 and C tumors among the patients referred after 3 or more endoscopi c attempts (33%) than after one or two sessions (10%) (p < 0.0003). We conf irm that in spite of multiple endoscopic biopsies, only a complete resectio n permits an exact staging and an appropriate therapeutic choice.