HISTOGENESIS OF SMALL COLONIC ADENOCARCINOMAS

It has been claimed that in order to identify the type of mucosal lesi on which precedes colonic adenocarcinoma only those tumours measuring less-than-or-equal-to 1 mm in diameter should be considered. The revie w of the English literature indicates that only 35 colorectal adenocar cinomas measuring less-than-or-equal-to 1 cm in diameter have been so far reported. From the three cases of colonic adenocarcinoma measuring 8 mm or less in diameter presented here, one adenocarcinoma originate d in a flat adenoma, the second in an exophytic tubular adenoma, and t he third showed no adenomatous component. It would thus appear that co lonic adenocarcinomas can originate not only from exophytic adenomas o r from flat adenomas but also from apparently nonadenomatous flat muco sa. (C) 1994 Wiley-Liss, Inc.