Is placing a VP shunt a major risk to spread medulloblastoma or other malignant brain tumors into the gut?

While most malignant primary brain tumors will NOT spread to the gut via VPS, case reports of pediatric brain tumors dominate the literature regarding this risk. Germ cell tumors are probably most commonly reported, followed by PNETs and medulloblastomas [Piatt and Garton, PMID 18431216, Kay et al., PMID 31876829]. The paucity of adult case reports suggests very few adult patients suffer this complication [Kim et al., PMID 30917830, Ng et al., PMID 29682040].

In my experience, the VPS stops working before any neoplastic spread occurs, likely due to proteinaceous or even cellular debris obstructing the valve mechanism or tubing.

I think the need for VPS outweighs the risk for such a complication.