Vaginal columnar cell metaplasia. An acquired adenosis associated with topical 5-fluorouracil therapy

Vaginal adenosis, with columnar epithelium of endocervical or endometrial type forming glands within the vagina, has been observed as a congenitally acquired process, associated with in utero exposure to diethylstilbestrol; approximately 20% of those women exposed in utero have adenosis. It has been observed that vaginal adenosis may occur in nonexposed women; the origin is thought to be acquired following puberty. This study analyzed eight patients who, following topical vaginal therapy with 5-fluorouracil for vaginal intraepithelial neoplasia, had unresolving, reddened areas in the upper one-third of the vagina. Biopsy of these areas demonstrated columnar epithelium on the vaginal surface, where stratified squamous epithelium would be expected. Superficial vaginal glands (adenosis) lined with epithelium identical to the surface columnar epithelium were also identified. This finding is consistent with a metaplastic process in which stratified squamous epithelium is replaced by columnar representing columnar cell metaplasia, or acquired vaginal adenosis.