Development of DES-associated clear-cell carcinoma: the importance of regular screening.

Because the rate of malignancies in young women exposed in utero to diethylstilbesterol (DES) is low, appropriate population screening methods have not been established. A case is presented that is believed to represent the first reported instance of a DES-exposed daughter who developed clear cell adenocarcinoma of the vagina after initially negative examinations. The patient was followed with Papanicolaou smears, pelvic examinations, and colposcopy every 6 months for 2 years prior to the discovery of malignancy. Initially negative, Papanicolaou smears successfully predicted the presence of an early adenocarcinoma. Palpation aided by colposcopy allowed directed biopsy of the small asymptomatic lesion. This case underscores the necessity for frequent vaginal cytologic smears and pelvic examinations at intervals no greater than 6 months. Colposcopy is indicated to direct biopsies when an abnormal cytologic smears is reported or when abnormal bleeding or discharge occurs. Biopsy of any palpable lesion is mandatory.