Neuro summary

When you see multiple SOL in old age , there are two main possibilities . Metastasis & primary CNS lymphoma (PCNSL) . but usually.,
- Metastasis tend to appear in the gray white junction due to the presence of microvasculature at this region which slows the flow velocity and has small lumen helping the large tumor cells to lodge .
- PCNSL : tend to appear in the deep structures around the ventricles due to the plenty of lymphocytes

gliomatosis is another possibility but it is rare

High grade meningiomas and gliomas usually show restricted diffusion while the low grades of both of them usually don't

craniocerebral topography continued
craniometric points part 3
The link is in the 1st comment