Adenocarcinoma in situ of the vagina: a case report.

The clinical and pathological features of a case of adenocarcinoma in situ of the vagina diagnosed in a 40-year-old woman with a negative history for intrauterine DES exposure are reported. The lesion was diagnosed 15 months following hysterectomy for in situ squamous cell and in situ adenocarcinoma of the cervix. The vaginal lesion closely resembled colposcopically, cytologically, and histologically previously described cases of cervical adenocarcinoma in situ. The case was of additional interest pathologically because of a focal signet-ring cell component which exhibited extensive pagetoid invasion of the adjacent squamous mucosa. No previously reported examples of vaginal adenocarcinoma in situ could be found. The histogenesis of this entity is briefly discussed.