Squamous neoplasia of vagina related to DES syndrome.

The emphasis to date in the DES syndrome has been confined to the presence of adenosis in the vagina and the occassional adenocarcinoma which may arise from this ectopic glandular epithelium (less than 250 to date). As these patients mature, however, the glandular epithelium in the vagina is replaced by squamous metaplastic epithelium. Forty-six patients with benign vaginal adenois were observed colposcopically for up to 2 years. Atypical squamous epithelium (white epithelium, punctation, or mosiac pattern) was observed in 40 of the 46 patients. Colposcopically directed biopsy revealed six cases ofdysplasia (mild to severe) and one unequivocal case of in situ squamous carcinoma. These squamous lesions in the vagina were identical, both colposcopically and histologically,to similiar lesions on the cervix. These data suggest that squamous neoplasia may be more frequent in the future of the DES-exposed patient than adenocarcinoma.