Topographic relation of cervical ectropion and vaginal adenosis to clear cell adenocarcinoma

Twenty specimens of uterus and vagina removed because of clear cell adenocarcinoma of the cervix or vagina in women exposed prenatally to diethylstilbestrol were serially blocked and sectioned to study the topographic relation between the carcinoma and the cervical ectropion and vaginal adenosis. Three tumors were cervical; 17 were vaginal. Iodine staining performed on 8 specimens indicated that the carcinoma developed consistently just above the distal limit of the cervical or vaginal surface that failed to stain with iodine, a location that usually corresponds to the distal limit of abnormality visible by colposcopic examination. Microscopic examination disclosed the presence of both cervical ectropion and vaginal adenosis in all the specimens. Mucinous glands were abundant above the tumor. In 18 of the 20 cases, tuboendometrial glands were intimately related to the carcinoma, either surrounding it or abutting its inferior border. These data, in addition to other evidence, suggest that tuboendometrial epithelium, whether in the ectocervix or vagina, provides the bed from which clear cell adenocarcinoma develops.