Vaginal and Cervical Abnormalities Related to Prenatal Exposure to Diethylstilbestrol (DES)

Abstract

Primary neoplasms of any type are uncommon in the vagina, with the malignant forms accounting for less than 2% of all cancers of the female genital tract. The most common type of cancer is the squamous cell carcinoma, which usually occurs in elderly women. Clear cell adenocarcinomas, which have also been called mesonephromas and mesonephric carcinomas, are much more rare. Prior to 1970 only sporadic cases were known to have occurred in older women and only four examples had been reported in young females.¹² When seven young women with clear cell adenocarcinoma of the vagina were unexpectedly encountered at the Massachusetts General Hospital between 1966 and 1969,¹² a search for a common factor in their medical histories led to the association of these tumors with exposure in utero to diethylstilbestrol (DES), a synthetic, nonsteroidal estrogen that had been administered to their mothers for high-risk pregnancy.¹⁵ Later, a highly significant but less constant association of clear cell adenocarcinoma of the cervix with prenatal exposure to DES became apparent. Nonneoplastic changes of the female genital tract, including vaginal adenosis and cervical erosion, were also found not only in the great majority of the cancer patients but subsequently in a high percentage of asymptomatic young females who had been exposed prenatally to DES and the chemically related drugs, hexestrol and dienestro1.^{1,3,5,8–15,25,29,32,33,36}