Scanning and transmission electron microscopic studies of vaginal adenosis and the cervical transformation zone in progeny exposed in utero to diethylstilbestrol.

Much attention has recently been focused on vaginal adenosis and other cervical and vaginal alterations occurring in female offspring exposed to diethylstilbestrol (DES) in utero. These alterations consist of heterotopic glandular epithelium in the vagina, a characteristic cervical transformation zone, and the frequent presence of a cervical collar, or hood. It is believed that these changes occur during embryonic differentiation of the lower genital tract following failure of squamous epithelium to migrate in a cephalad direction to replace columnar epithelium which normally lines the vagina and ectocervix. A number of cases clear-cell carcinoma have occurred in DES-exposed girls who also had adenosis. In an attempt to characterize the cellular populations of these areas of adenosis, we have made an ultrastructural study which is herein reported.