[Immunohistochemical studies on colorectal adenoma and carcinoma--correlation of cellular dysplasia and intracellular CEA distribution, lectin-binding sites and quantities of nuclear Feulgen DNA content].

Intracellular distribution of CEA, lectin binding sites including PNA, DBA and UEA-1, and quantity of nuclear DNA content were examined in 54 adenomas and 29 carcinomas of the colorectum. CEA was found in 40% and 60% of adenomas with mild and moderate dysplasia, and all carcinomas. In particular CEA which was diffusely distributed in the cytoplasm was found in 9% and 26% of adenomas with mild and moderate dysplasia, and in 79% of carcinomas. Both PNA and DBA were shown to have different binding sites in non-tumorous mucosa, adenoma and carcinoma. However, no difference was found in the binding sites of adenomas with different grades of dysplasia. Whereas, the binding sites of UEA-1 were demonstrated to differ with the degree of dysplasia in adenomas and also carcinomas: UEA-1 binding in the brush border was found to be 29%, 63%, and 80% in adenomas with mild and moderate dysplasia, and carcinomas respectively. Nuclear Feulgen DNA content increased in parallel with the grade of cellular dysplasia. All carcinomas exhibited polyploid cell over 4C greater than 8%. Thirty percent of adenomas with moderate dysplasia also showed the same polyploid cells as carcinomas. These results suggest that the changes of CEA distribution, binding sites of lectins and of nuclear Feulgen DNA in adenoma may indicate its malignant potential in the colorectum, and that these changes may occur before any histological malignant transformation.