Metastatic tumors to the urinary bladder: clinicopathologic study of 11 cases.

Secondary neoplasms of the urinary bladder are uncommon, with metastatic tumors being an even rarer event. The authors studied the clinicopathology of 11 cases of metastatic tumors to bladder, which were collected from their archives between 1995 and 2010. The most common metastases in this series were breast. Some unusual metastases, including several not being previously reported, were also presented, namely, ileal carcinoid tumor, ileal gastrointestinal stromal tumor, ovarian squamous carcinoma, pancreatic gastrinoma, and renal collecting duct carcinoma. Vast majority of these patients (10/11, 91%) were female. Ninety percent of the patients presented with hematuria and/or obstructive urinary symptom as well as bladder lesions in the area of trigone, posterior wall, and/or bladder neck. Seven of the 11 patients had a known history of other metastases besides the bladder. Most of the patients (4/7, 57%) died within 1 year after diagnosis of bladder metastasis. Metastasis must be distinguished from a primary bladder neoplasm. Morphology and clinical correlation supplemented with immunohistochemical study is critical for the correct diagnosis.