Treatment of malignant polyps.

From 1975 to 1993, at the Division of Diagnostics and Endoscopic Surgery of the Istituto Nazionale Tumori in Milan, 191 malignant adenomas of colon-rectum have been endoscopically removed. On the basis of histopathologic criteria, endoscopic treatment has been judged adequate in 102 cases (53%), not adequate in 44 (23%), doubtfully adequate in 45 (24%). In 84 patients (44%) endoscopic polypectomy has been followed by surgical resection of the involved intestinal tract, 107 patients (56%) have been treated only by endoscopy. Results have been evaluated on the basis of surgical specimen, clinical follow-up and survival, showing that criteria we have adopted for the adequacy of the endoscopic treatment have a high negative predictive value (96%) and a low positive predictive value (32%). Actuarial survival of patients treated only endoscopically is 97% at 5 years and 95% at 10 years.