What is clear cell adenocarcinoma?

➢ Identified in 1970, in a cluster of young women whose mothers took DES during pregnancy to prevent threatened abortion. ➢ The incidence of this tumor in persons exposed to DES in utero is low (<1 per 1000, albeit about 40 times greater than in the unexposed population). ➢ In about 1/3 of exposed women, small glandular or microcystic inclusions develop in the vaginal mucosa. ➢ These lesions appear as red, granular foci lined by mucussecreting or ciliated columnar cells : This condition is called vaginal adenosis and is benign but is important to recognize because it is from such precursor lesions that clear cell adenocarcinoma arises.