Astrocytic Brain tumors

 

Astrocytic Brain 

Deffinition: diffusely infiltrating gliomas (WHO grades II–IV).

Epidemiology and natural history

1. Most frequent neoplasms of the CNS (60%), with incidence 5–7/100,000 person-years. 
2. Grade II (diffuse astrocytomas): 5–10%. 
3. Grade III (anaplastic astrocytomas): 10% (distinguished from grade II by mitotic activity). 
4. Grade IV (glioblastoma): 80%; can progress from lower grade tumors or arise de novo. Tumor progression following treatment may be confused with radiation necrosis. Further distinction with necrosis (sometimes pseudopallisading) and microvascular proliferation. 
5. Dedifferentiation from low grade to high grade occurs sooner with age > 45 years 1–20% present as multiple gliomas

Classifications of  Tumor

Epidemiology/natural history of diffusely infiltrating astrocytomas

Treatment 

1. Diagnostic surgical biopsy or partial resection recommended in almost all cases. Gross total resection is the best option if tumor location and patient condition permits. 
2. Treatment options for low-grade lesions include serial follow-up, radiation and/or chemotherapy, and surgery (no clearly superior strategy). Aggressive treatment may be appropriate for more aggressive tumors (in case of young patients, large tumors that enhance, or patients with short clinical history or progression on imaging). 
3. Standard treatment for high-grade lesions is gross total resection followed by external beam radiation and temozolomide chemotherapy. Extent of resection is correlated with survival. Poor prognosis with older patients (> 60), glioblastoma (WHO grade IV) histology , poor preoperative performance (Karnofsky) status.