tumor grade
Histopathological classification system indicating the degree of malignancy and aggressiveness of brain tumors.
Full Definition
Tumor grade in neurosurgical oncology refers to the histopathological classification that indicates the degree of malignancy and biological aggressiveness of brain neoplasms. The World Health Organization (WHO) classification system grades central nervous system tumors from I to IV, with Grade I representing the most benign tumors with excellent prognosis, and Grade IV indicating the most malignant tumors with poor prognosis. Grading is based on specific histological criteria including cellular atypia, mitotic activity, endothelial proliferation, and necrosis. Higher-grade tumors typically grow more rapidly, are more likely to recur after treatment, and have shorter survival times. Tumor grade is crucial for determining treatment protocols, predicting prognosis, and guiding follow-up care.
Usage
Usage note: Roman numerals I-IV used; not to be confused with TNM staging system.
In Context
- "Pathology confirmed a tumor grade of III with increased mitotic activity and vascular proliferation." — pathology report
- "The tumor grade determines the aggressiveness of adjuvant therapy required." — treatment planning discussion