Scanning electron microscopy of 'normal' urothelium in patients with infiltrating bladder carcinoma.

'Normal' dome biopsies from 20 cystectomies for infiltrating bladder carcinomas were studied with scanning electron microscopy (SEM). All cases showed alterations ranging from minimal changes to numerous pleomorphic microvilli, and were classified according to Herd and Jacobs. The SEM findings and grades were correlated with dome histology and the results were quite good. However, in our opinion, the Herd and Jacobs classification and subclassifications are poorly reproducible without morphometric analysis. Nevertheless the SEM study is useful to strengthen the diagnosis of dysplasia/carcinoma in situ in 'healthy'-looking urothelium.