Carcinoma of the Urinary Bladder

Abstract

CARCINOMA of the urinary bladder is primarily a disease of the elderly, with a peak incidence among those 60 to 70 years old. Each year approximately 9,000 persons in the United States die of urinary bladder cancer, the incidence being three times as frequent in men as in women. The cause of the vast majority of urinary bladder tumors has not been determined. Nevertheless, several causative agents (such as 2-naphthalamine, xenylamine, 4-nitrobiphenyl, benzidine, phenacetin, and caffeine) have been identified as carcinogens, and an increased incidence of bladder carcinoma is reported in workers in the rubber, printing, and leather industries.¹ Most bladder carcinomas are transitional cell tumors of varying degrees of differentiation. Squamous cell metaplasia is seen in many transitional cell carcinomas, particularly the less well-differentiated ones. However, except when schistosomiasis is the cause, true squamous cell carcinomas are rare. Adenocarcinomas also are uncommon. On initial examination, the commonest sign