Characteristics of Colorectal Epithelia and Adenomas as Revealed by DNA Cytofluorometry

: Human colorectal normal epithelia and tubular adenomas were studied by DNA-cytofluorometry using free cell nuclei isolated from formalin-fixed and paraffin-embedded specimens. All the normal epithelia (30 cases) showed low proliferative activity, no polyploid cells and no aneuploid cell clones at any age in either sex. The mean diploid G1/G0 fraction (DF) of the normal epithelia was 95.9%. The adenomas, on the other hand, showed increased proliferative activity usually in accordance with the grade of atypia. The mean DF values of the adenomas with mild atypia (31 lesions) and moderate atypia (21 lesions) were 89.4% and 85.6%, respectively. The adenomas, irrespective of their grade of atypia, occasionally showed low proliferative activity, while in the adenomas adjacent to a carcinoma, the proliferative activity was relatively high even though their atypia was mild. Neither polyploid cells nor aneuploid cell clones were found in the adenomas. Therefore, polyploid and aneuploid cell populations are characteristics of carcinoma of the colon and rectum, and this criterion should be useful in investigations of the genesis of carcinoma in the human colorectal mucosa.