Pathologic significance of polyps of the rectum and colon

Conclusions Since cancers and adenomatous polyps of the colon are indistinguishable except by histologic examination, all rectal and lower sigmoidal polypoid tumors seen through a sigmoidoscope should be removed for histologic examination. Juvenile (retention) polyps usually require no further treatment. Adenomatous polyps with focal atypia, carcinomain situ and noninvasive cancer are curable by adequate local excision. Villous (papillary) adenomas so frequently contain invasive cancer that they must be resected as cancers. If a polypoid tumor is entirely cancerous, a radical resection should be performed. The only significant physical characteristic of small polypoid tumors situated beyond reach of the sigmoidoscope that can be correlated with the presence of cancer is its size. The chance of a tumor, 1.2 cm. in diameter or greater, being a cancer is more significant than the mortality rate attending its removal either by colotomy with polypectomy or open segmental resection. Removal of tumors, 1.2 cm. in diameter or smaller, must be accomplished with a mortality rate of less than 1 per cent in order to avoid substitution of an iatrogenic death rate for a neoplasic death rate. Based on the doubling time concept, data have been presented to show that, when necessary, small colonic polypoid tumors situated beyond range of the sigmoidoscope may be observed for increases in size, the earliest indication of cancer, by repetition of the roentgenologic examination of the colon after barium enema at intervals of three to six months.