Low grade astrocytoma: 

Occurs in adults
- Mean survival 6-8 years
- Differentiate from Anaplastic (who III), which has more anaplasia and more mitoses, and GBM which has tumor necrosis and endothelial proliferation
- Can transform into higher grade astrocytomas over time.

Gross path:
- No discrete circumscribed lesion
- Diffuse expansion of the brain parenchyma.

Path:

- Increased cellularity of brain 

- Ovoid to elongated nuclei, hyperchromasia 

- gemistocytes - pink inclusions around nuclei, indicate reactive astrocyte
- must have > 20% gemistocytes to be considered a "gemistocytic" tumor (oligos and others can have occasional gemistocytes)
- worse prognosis than WHO-grade matched controls

T1 dark, T2 bright, non-enhancing

source: headneckbrainspine.com