Spread of supratentorial PNETS can be thought of in terms of:
- Local:
- Invasion of adjacent brain
- CSF pathways:
- Leptomeninges are often involved in at least 30% of patients at diagnosis or relapse
- Distant:
- Extraneural metastases are very uncommon6 (in one series <0.5% had metastases outside the CNS11)
- Unless patients are symptomatic, bone scans and bone marrow biopsy to detect metastatic disease outside the CNS would not be routinely recommended in patients with newly diagnosed disease
