Genital warts and cervical cancer. V. The tissue basis of colposcopic change.

Histologic differences between subclinical papillomaviral infection and cervical intraepithelial neoplasia are quantitative rather than qualitative. Both entities are characterized colposcopically by acetowhite epithelium and aberrant surface capillaries. This study correlates five new colposcopic signs (variations in contour, thickness, color, vascular patterns, and iodine staining) with 12 histologic signs of human papillomaviral infection and 12 features of premalignant change. Acetowhitening and capillary abnormalities in minor colposcopic lesions are attributable to human papillomaviral disturbance of cell growth and maturation, seen histologically as parabasal layer proliferation, papillomatosis, koilocytosis , and dyskeratosis. Alteration in cell ploidy is usually minimal. Major colposcopic abnormalities reflect extensive disorganization of cell phenotype and tissue architecture, increased DNA content, and aneuploid stem cell populations. Intermediate colposcopic patterns generally denote polyploid lesions in which tissue changes are a composite of two reciprocal events: the extent of benign warty expression and the severity of premalignant change.