WHO grading system
Also written as: WHO — World Health Organization
The World Health Organization's standardized classification system for grading bone and soft tissue sarcomas based on histological features.
Full Definition
The WHO grading system is the internationally accepted standard for classifying bone and soft tissue sarcomas based on histological criteria including cellular differentiation, mitotic activity, and necrosis. The system typically employs a three-tier grading scale (Grade 1: low-grade, Grade 2: intermediate-grade, Grade 3: high-grade) that correlates with clinical behavior, metastatic potential, and prognosis. This grading system is essential for treatment planning, as it influences decisions regarding adjuvant therapy, surgical margins, and follow-up protocols. The WHO classification is regularly updated to incorporate new molecular and genetic findings.
Usage
Usage note: Always specify the WHO classification edition being used, as criteria may change between updates.
In Context
- "The tumor was classified as Grade 3 according to the WHO grading system." — Pathology report
- "WHO grading system criteria were applied to determine the need for adjuvant chemotherapy." — Treatment planning