Pathologic risk factors of occult malignancy in endoscopically unresectable colonic adenomas

BACKGROUND: With the advent of new endoscopic and laparoscopic techniques, the likelihood of colonoscopically unresectable adenomas harboring occult m alignancy influences management. While prior studies have evaluated polyp s ize and morphology in assessing the risk of malignancy, the relative risk o f cancer based on the presence or absence of high-grade dysplasia has not b een systematically studied, METHODS: For all lesions preoperatively diagnosed as adenomas without invas ive cancer, multivariate logistic regression analysis was performed to elic it independent variables associated with malignancy in the resected specime n. RESULTS: One hundred patients underwent a colectomy for preoperatively diag nosed adenomatous lesions. Multivariate logistic regression analysis reveal ed size, degree of dysplasia, and left-sided location to be independent pre dictors of malignancy. CONCLUSIONS: In colonic adenomas which are not amenable to simple colonosco pic resection, the most useful predictors of the lesion harboring a maligna ncy are polyp size and the presence of high-grade dysplasia, and these fact ors can help determine management. Am J Surg. 1999;177: 384-887. (C) 1999 b y Excerpta Medica, Inc.