Nonpapillary carcinoma in situ and atypical hyperplasia in cancerous bladders: further studies of surgically removed bladders by mapping.

Complete mapping of epithelium has been performed in 10 bladders surigcally removed for cancer. In all cases, in areas adjacent to or distant from the visible tumors, nonpapillary carcinoma in situ and related lesions such as atypical hyperplasia could be demonstrated. More importantly, in 5 of the 10 bladders, areas of occult invasive carcinoma derived from such abnormal epithelia have been recorded. These findings fully confirm prior observations and raise the number of totally mapped bladders to 20. The histologic findings in the entire series of 20 cases are discussed and the distribution of cancer and precancerous lesions tabulated. It is suggested that the areas of the bladder most frequently affected by precancerous lesions are the left and right lateral walls and the posterior wall. The trigone and the dome are less frequently involved. The need for aggressive assessment of bladder epithelium in patients with tumors of the bladder and/or early radical treatment for patients with non papillary carcinoma in situ is discussed in light of these observations.