Risk Factors for Delayed Leptomeningeal Dissemination in Choroid Plexus Papillomas: A Systematic Review and Illustrative Case.

PURPOSE: Choroid plexus papilloma (CPP) is a rare, benign intraventricular tumor that typically has an excellent long-term survival rate after gross total resection. Nevertheless, some patients develop delayed leptomeningeal dissemination (LMD) years after the initial diagnosis, a phenomenon that remains poorly understood. The authors encountered a case of CPP with delayed LMD 14 years after resection, which prompted this systematic review to identify potential risk factors.

METHODS

A systematic review was conducted according to PRISMA guidelines to identify CPP reports with subsequent delayed LMD. Studies of atypical CPP, choroid plexus carcinoma, or concurrent LMD at diagnosis were excluded. Extracted variables included demographics, tumor location, extent of resection, recurrence, proliferative index, and latency to dissemination.

RESULTS

Thirty patients developed delayed LMD after initial diagnosis. Seventeen patients underwent gross total resection, ten underwent subtotal resection, and three were unreported. Delayed LMD occurred with tumor recurrence in 14 patients. Histological transformation was observed in nine patients: eight progressed to aCPP and one to CPC. The extent of resection, recurrence, and tumor transformation were not significantly associated with delayed LMD.

CONCLUSIONS

The pathogenesis and optimal treatment strategy of this phenomenon remain unclear. No significant risk factors for delayed LMD development in CPP were identified. Future studies incorporating molecular characterization are needed to clarify the mechanisms of LMD in patients with CPP and to improve risk stratification, underscoring the importance of lifelong surveillance and the integration of molecular profiling in clinical management.