Bladder cancer is a type of abnormal cell malignancy that begins in the cells of the bladder, the balloon-shaped organ which functions as a waste storage system for urine.
Transitional cell (urothelial) carcinoma: is cancer that begins in the urinary tract transitional epithelium cells lining the inside of the bladder. Transitional cell carcinoma is the most common kind of bladder cancer, occurring in about 95% of cases.
Squamous cell carcinoma: is cancer that begins when epithelial cells change to squamous cells (thin, flat cells) as a result of chronic irritation and inflammation. About 1% to 2% of bladder cancers are squamous cell carcinomas.
Adenocarcinoma: is cancer that begins in the cells of glandular structures lining the inner lining of the bladder. Adenocarcinomas account for only about 1% of bladder cancers.