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

## TL;DR

This paper reviews cases of choroid plexus papilloma patients who developed delayed leptomeningeal dissemination and finds no clear risk factors for this rare complication.

## Contribution

The study is the first systematic review to analyze risk factors for delayed leptomeningeal dissemination in choroid plexus papilloma patients.

## Key findings

- Thirty patients developed delayed leptomeningeal dissemination after choroid plexus papilloma diagnosis.
- No significant associations were found between delayed dissemination and resection extent, recurrence, or tumor transformation.
- Future research should focus on molecular characterization to understand dissemination mechanisms.

## Abstract

Choroid plexus papilloma is a benign intraventricular tumor with an excellent long-term survival rate after gross total resection. However, some patients develop delayed leptomeningeal dissemination years after the initial diagnosis, a phenomenon that remains poorly understood. A systematic review was conducted to identify reports of patients with subsequent delayed leptomeningeal dissemination. The review identified thirty patients who developed delayed leptomeningeal dissemination after initial diagnosis. The extent of resection, recurrence, and tumor transformation were not significantly associated with delayed leptomeningeal dissemination. The pathogenesis and optimal treatment strategy for this phenomenon remain unclear, as we could not identify any significant risk factors for delayed leptomeningeal dissemination in choroid plexus papilloma.

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.