Development of the human colonic adenocarcinoma from adenoma as a histopathologically continuous process.

Abstract

The adenocarcinoma sequence of the human colon is usually divided into three separate steps according to the grade of epithelial dysplasia, i.e., adenomas with mild, moderate and severe dysplasia. In an attempt to re-examine whether or not this sequence can be morphologically separable as usually assumed, a total of 192 epithelial lesions including adenomas with various grades of dysplasia were analyzed, relying on morphometrical and multivariate-statistical techniques. Histologic features of epithelial lesions were characterized by 10 quantitative parameters and subjected to 10-variate cluster analysis. In the result of computations, separation of neoplastic lesions into different groups proved to be rather ambiguous, not justifying the classification into three groups as generally expected. It was concluded that adenocarcinoma can develop from adenoma as a seemingly continuous process which may involve more steps than usually assumed.