Practical & Controversial Issues in Diagnosis, Grading and Staging of Urothelial Carcinoma: an Approach

DIAGNOSIS: A. All that is papillary in the bladder is not papillary urothelial neoplasia: i. Diagnostic pitfalls: papillary hyperplasia, nephrogenic adenoma, fibroepithelial polyp and papillary/polypoid cystitis ii. Artifacts: pseudopapillary folds and avulsed urothelium B. All urothelial proliferations that expand the lamina propria are not invasive carcinoma: i. Diagnostic pitfalls: florid von Brunn nests and pseudocarcinomatous hyperplasia C. Formes frustes of papillary urothelial neoplasia: i. Papillary hyperplasia ii. Dysplasia/CIS with early papillary formations iii. Truncated papillae of treated urothelial neoplasia iv. Bulbous inverted prolongations without surface papillary component D. Pitfalls in the diagnosis of flat lesions: i. Radiation and chemotherapy related atypia ii. Reactive atypia iii. Human polyoma virus