Serous adenocarcinoma of the uterus metastatic to the urinary bladder mimicking primary bladder neoplasia. A report of a case.

A 72-year-old woman with a history of transitional cell carcinoma of the urinary bladder was found to have a vesical neoplasm at cystoscopy. Microscopic examination of a biopsy specimen showed papillary adenocarcinoma. A subsequent endometrial biopsy, performed because of vaginal spotting, disclosed a serous papillary adenocarcinoma. A hysterectomy was performed. Pathologic examination showed that the tumor was deeply invasive of the myometrium. The uterine and bladder tumors were similar histologically. This case suggests that when examining a pure adenocarcinoma of the bladder, the pathologist should consider the possibility that it represents metastatic disease even in the absence of a known tumor elsewhere.