What's new in WHO fifth edition - urinary tract

Area of Science:

• Uropathology and oncology.
• Molecular diagnostics in urological cancers.

Background:

• The WHO Blue Book is a critical resource for classifying urological tumours.
• Previous editions introduced significant changes to bladder tumour classification.
• Advancements in molecular biology necessitate updated classifications.

Purpose of the Study:

• To detail the updates in the bladder tumour classification in the 5th edition of the WHO Blue Book.
• To incorporate molecular findings into urothelial tumour classification.
• To address key challenges in bladder pathology.

Main Methods:

• Review and synthesis of the bladder cancer chapter from the 5th edition WHO Blue Book.
• Integration of recent molecular research findings.
• Focus on specific areas: grading, heterogeneous lesions, inverted tumours, and substaging.

Main Results:

• Refined classification of bladder tumours based on updated criteria.
• Inclusion of molecular stratifiers for precision treatment of urothelial tumours.
• Clarification on grading, heterogeneous lesions, inverted tumours, and substaging.

Conclusions:

• The 5th edition WHO Blue Book provides an updated framework for bladder tumour classification.
• Molecular insights are crucial for precision oncology in bladder cancer.
• The updated guidelines address critical areas of diagnostic uncertainty.