Vaginal adenosis: A precancerous lesion?

Abstract

The prenatal administration of diethylstilbestrol (DES) during the period of vaginal organogenesis alters the embryologic localization of the original squamocolumnar junction which may be established anywhere in the vagina rather than on the cervix. Exposure of the columnar epithelium to the vaginal environment and to the low pH of the vagina stimulates the development of squamous metaplasia. Colposcopically, this squamous metaplasia is part of a large transformation zone which, in some cases, involves the entire vagina. The major clinical significance of this entity concerns the fact that in DES-exposed girls, abnormal colposcopic findings (white epithelium, mosaic pattern, punctation) are present within the transformation zone in 97 per cent of cases, as compared to only 8 per cent in unexposed girls. This highly significant difference suggests that the major clinical risk in DES-exposed girls is the potential development of squamous neoplasia rather than the rare associated case of clear-cell adenocarcinoma. In a colposcopic and histologic study of 131 cases of vaginal adenosis in DES-exposed girls, two cases of squamous carcinoma in situ, two cases of severe dysplasia, and three cases of moderate dysplasia were diagnosed.