The urinary bladder is the most easily accessible of the internal organs; its normal histologic charracteristics are quite simple, and most of its tumors are of epithelial origin. Yet, regrettably, there are no generally accepted pathological criteria for the diagnosis of malignancy, and there is no unanimity on a standard pathological classification or nomenclature of these tumors. What is designated as a papilloma by one pathologist may be called a urothelioma or a urothelial, papillary, transitional cell, or squamous cell carcinoma by others.11 It has been impossible to assess the results of various forms of therapy or to compare epidemiologic, survival, mortality, or other data.
It is the purpose of this communication to review the areas of disagreement and to propose a tumor classification of clinicopathologic value.
Criteria for the Diagnosis of Carcinoma of the Bladder
Although 97% of tumors of the bladder are of epithelial origin, and, in