Detection of neoplastic and preneoplastic urothelia by combined scanning and transmission electron microscopy of urinary surface of human and rat bladders

Abstract

Scanning and transmission electron microscopy reveal distinct differences between the appearance of the luminal surface membrane of normal urothelium and those of transitional cell tumors of human and rat bladders. The luminal surface membrane of the preneoplastic rat urothelium shows features similar to those seen in the fully developed tumors. In human tumor-bearing bladders the urothelium away from the transitional cell tumor is not recognizable as being preneoplastic by light microscopy. By scanning or transmission electron microscopy, the luminal membrane in some areas shows changes identical to those in the preneoplastic rat bladder. These observations are in accordance with the clinical behavior of the urothelium in patients with vesical transitional cell tumors which tend to recur in disparate sites. Scanning electron microscopy of the bladder urothelium away from the tumor may be of prognostic value for indicating the subsequent biological behavior of the urothelium.