anaplastic astrocytoma
A grade III malignant brain tumor arising from astrocytes, characterized by increased cellularity and mitotic activity compared to lower-grade astrocytomas.
Full Definition
Anaplastic astrocytoma represents a grade III glioma according to WHO classification, arising from astrocytic cells in the brain. These tumors demonstrate increased cellularity, nuclear atypia, and mitotic activity compared to grade II astrocytomas but lack the microvascular proliferation and necrosis seen in glioblastoma. They typically occur in adults and have an intermediate prognosis between low-grade gliomas and glioblastoma. Treatment usually involves maximal safe resection followed by radiation therapy and chemotherapy.
Usage
Usage note: Always specify WHO grade when first mentioned in clinical documentation.
In Context
- "The pathology report confirmed anaplastic astrocytoma with IDH1 mutation." — Pathology report
- "Treatment planning for anaplastic astrocytoma typically includes adjuvant radiotherapy." — Treatment protocol