Flow cytometry of polypoid neoplasms of the colon resected by endoscopy

Sixty-one neoplastic polypoid lesions of the large bowel and rectum, obtained by endoscopic resection, were submitted to cytofluorometric measurements. This study was performed on archival formalin fixed and paraffin embedded material using the method of Hedley. Coefficient of variation, DNA Index, DNA aneuploidy, proliferative activity were statistically correlated to histological grading (according to U.I.C.C.) and to the presence of trophic changes (epithelial displacement, hemorrhage, mucus discharge. Compared with morphological findings, cytofluorometric results revealed that DNA aneuploidy appeared only when intraepithelial carcinomatous changes were present, and was found in 50 percent of microinvasive carcinoma. The proliferative activity was significantly increased in intraepithelial carcinomas, with a significant enlargement of the coefficient of variation. This change may reflect initial disorders in DNA content of neoplastic cells. On the other hand, there was no significant difference between lesions with and without trophic alterations. These findings confirm that this increase is an independent phenomenon during tumor progression.