Histological inhomogeneity of colorectal adenocarcinomas.

The histological inhomogeneity of colorectal adenocarcinomas has hardly been systematically investigated up to now. Currently, however, this awareness is gaining in importance, e.g. within the framework of grading measures, for analysis of immunohistochemical results or for interpretation of flowcytometric data. Thus, 100 colon carcinomas each were semiquantitatively investigated on four different sites in terms of either homogeneous or inhomogeneous expression of histological, cytological and immunohistochemical (CEA, UEA I) criteria. Although all carcinomas contained tubular structures, there was no intraindividual uniformity but considerable inhomogeneity on the part of histological as well as cytological features. Quantitative and qualitative positivity of CEA and UEA I too, varied markedly. Our results lead to the conclusion that the phenotypic inhomogeneity of colorectal carcinoma is at least partially attributable to genetic tumor cell instability. In spite of this, there might be a trend to intra-individual localisation-related tumor cell differentiation, because several parameters showed significant differences between luminal and deep carcinoma regions.