The significance of microscopic invasive cancer in endoscopically removed polyps of the large bowel. A clinicopathologic study of 51 cases.

A clinicopathologic study of 51 patients with endoscopically removed large bowel polyps showing histologic evidence of malignancy, either focally, to a massive extent, or comprising the entire polyp, revealed only one absolute finding capable of predicting residual disease, namely, the presence of cancer at the resection line. Of 23 radical resections, only one was justified. This case showed evidence of residual disease in the colectomy specimen that could have been predicted on the basis of involvement of the diathermy margin by carcinoma. Of 28 patients having polypectomy alone, 1 patient developed a Dukes' B carcinoma. The polyp, removed 9 months previously from the same site, had shown involvement of the margin by carcinoma. A conservative approach is thus advocated in the absence of this finding.