STEREOLOGICAL ASSESSMENT OF ARCHITECTURAL CHANGES IN DYSPLASTIC EPITHELIUM OF COLORECTAL ADENOMAS

Background: Against the background of developing quantitative prognost ic indicators for the future risk of colorectal cancer in adenoma bear ing-patients, the possibilities of stereological measuring techniques for providing objective measures of architectural changes in colorecta l adenomas were examined. Material and Methods: The haematoxylin-eosin stained tissue sections of 59 adenomas, of which 20 showed mild dyspl asia, 20 moderate dysplasis, and 19 severe dysplasia, were assessed. U sing a projection microscope equipped with a coherent test system that was specifically ''designed to analyze anisotropic tissue, the volume density of stroma, epithelium and lumen, the outer and the inner glan d surface density, and the length density lumen were determined. Resul ts: With respect to grading, significant differences in the means of t he inner gland surface density and the length density lumen were found mainly between mild and severe dysplasia as well as between moderate and severe dysplasia. This was especially evident when considering the subgroup of tubular adenomas. Stepwise discriminant analysis resulted in an overall correct jackknifed classification of 81.3 % when mild a nd moderate dysplasia cases were taken as one group, and were compared with the group of severe dysplasia cases. With respect to histologica l type, the volume density lumen and the outer surface density glands, were most favourable. These two features allowed for an 87.5 % overal l correct jackknifed classification of tubular adenomas, versus adenom as with villous components. The analysis time was roughly 30 minutes p er polyp. Intra-observer reproducibility was satisfying, with CE-value s less-than-or-equal-to 5 % for all variables. Inter-observer reproduc ibility tests were encouraging. Conclusions: The application of stereo logical techniques can be worthwhile in assisting in the classificatio n of colorectal adenomatous polyps. Such techniques could therefore be a useful tool to estimate the prognostic value of adenoma morphology with respect to the development of metachronous colorectal tumours.