Vulval and vaginal adenosis.

Vaginal adenosis is defined by the presence of metaplastic cervical or endometrial epithelium within the vaginal wall, thought to be derived from persistent Müllerian (synonymous with paramesonephric) epithelium islets in postembryonic life. Spontaneous vaginal adenosis appears to be a fairly common (present in about 10% of adult women) but mostly insignificant coincidental finding. In women prenatally exposed to diethylstilboestrol (DES), vaginal adenosis may arise in up to 90% and is associated with a high risk of vaginal carcinoma.