Urothelial papillary (exophytic) neoplasms.

Area of Science:

• Uropathology
• Oncology
• Neoplasm Classification

Background:

• Contemporary classification of human papillary urothelial neoplasms is unsettled.
• Recent grading schemes lack clinical input and aim to avoid the term "cancer" for low-risk neoplasms.
• Previous grading systems were criticized for imprecision.

Purpose of the Study:

• To summarize the findings of Committee No. 1 at the International Consultation on the Diagnosis of Non-Invasive Urothelial Neoplasms.
• To evaluate existing classification and grading schemes for urothelial neoplasms.
• To provide a multidisciplinary consensus on the best classification approach.

Main Methods:

• Multidisciplinary international expert deliberation.
• Review of existing data and practical classification methods.
• Comparison of WHO 1973, WHO/ISUP 1998, and WHO 1999 classification schemes.

Main Results:

• The WHO 1973 classification for papillary urothelial neoplasms (papilloma, grade 1, grade 2, and grade 3 carcinoma) remains superior to alternatives.
• Refinement of diagnostic criteria for the WHO 1973 scheme would be beneficial.
• Synonymous classification reporting in other schemes is discouraged due to translation difficulties.

Conclusions:

• The WHO 1973 classification provides the most clinically useful framework for papillary urothelial neoplasms.
• Further refinement of diagnostic criteria can enhance the precision of the WHO 1973 system.
• A unified, internationally recognized classification is crucial for accurate diagnosis and patient management.