Diethylstilbestrol-associated vaginal adenosis followed by clear cell adenocarcinoma

A young woman was examined because of a history of in utero exposure to diethylstilbestrol and was identified as having vaginal adenosis. Fourteen months later, on routine follow-up, a small vaginal clear cell adenocarcinoma was recognized. She refused any therapy other than wide local excision. She was seen intermittently for several years with no recurrence. Five and one-half years after initial diagnosis she was found to have multiple sites of clear cell adenocarcinoma in the upper third of the lateral and anterior vaginal walls. Cases of vaginal adenosis followed later by the development of clear cell adenocarcinoma (metachronous cases) are distinctly unusual. The authors have collected the other recorded cases in the literature or in the Registry for Research on Hormonal Transplacental Carcinogenesis and have attempted to compare these cases with the larger group of patients who present with clear cell adenocarcinoma and have associated vaginal adenosis (synchronous cases). The authors have found few differences between the two groups. Most of the differences can be accounted for by the close follow-up of patients with known vaginal adenosis. However, it has been noted that the location of the clear cell adenocarcinoma is apparently different in the two groups. The reasons for this apparent difference are briefly discussed.