Clinical and therapeutic insights into intraventricular metastases from extracranial solid tumors: Patterns, prognosis and management

Abstract

Solid intraventricular metastasis from extracranial primary tumors (SIMs) are rare and their diagnosis and management remain poorly understood. A systematic review was conducted using the MEDLINE and Embase databases to identify relevant studies published until November 2024. Data such as presenting symptoms, treatments and survival outcomes were extracted from included articles on patients with SIMs. A total of 26 studies, involving 26 patients (34.6% female patients; median age, 64 years), met the inclusion criteria. The most common primary tumor was renal cell carcinoma (38.5%). Furthermore, 57.7% of patients had metastasis to one or both lateral ventricles, 19.2% had metastasis to the lateral and fourth ventricle, 11.5% had metastasis to the third ventricle alone, 7.7% had metastasis to the lateral and third ventricle, and 3.8% had metastasis to the fourth ventricle alone. Treatment approaches varied, with tumor resection (42.3%) being the most common intervention, followed by tumor resection with adjuvant chemo/radiation therapy (15.4%). The median post-treatment survival time was 4.3 months. Patients receiving tumor resection combined with radiation or chemotherapy had the longest survival (median, 24 months), compared with those undergoing tumor resection alone (median, 2 months). SIMs are rare but clinically significant, with variable treatment approaches and survival outcomes. Multimodal therapy offers the best prognosis, although survival remains generally poor. Further research is needed to better understand the pathophysiology, treatment strategies and outcomes of SIMs.

Keywords: choroid plexus; intraventricular; management; metastases; multimodal treatment.

Figure 1

Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram. A total of 26 articles were included in the final analysis.

Figure 2

Prevalence of primary tumors and ventricular location of metastasis. (A) Prevalence of the different primary tumors in the present cohort, with patients with RCC having the highest prevalence, followed by those with thyroid carcinoma and lung adenocarcinoma. Other primary tumors, such as breast, gastric, rectal, submandibular and prostate carcinomas were found to be less likely to metastasize to the intraventricular space. (B) Prevalence of intraventricular metastasis based on ventricular location. The lateral ventricle was the most common site of metastatic spread, followed by metastasis to the fourth ventricle, and the least common site of metastasis was the third ventricle. Created in BioRender. Arunachalam Sakthiyendran, N. (2025). RCC, renal cell carcinoma.

Figure 3

Pie chart of treatment modalities. Prevalence of the different management strategies employed to treat intraventricular metastasis in the present cohort of patients. CSF/IVB FD, cerebrospinal fluid/intraventricular bleeding flow diversion.

Figure 4

Kaplan-Meier analysis of the post-treatment survival duration for different primary tumors and treatment paradigms. (A) Kaplan Meier curve indicating that patients with thyroid carcinoma had the highest probability of survival up to 12 months post-treatment. However, after 12-months, patients with RCC had the highest probability of survival. Patients with lung adenocarcinoma had the shortest post-treatment survival duration across all timepoints. (B) Kaplan Meier curve indicating that patients who received resection and adjuvant chemo/radiation therapy had the highest survival probability at all timepoints post-treatment. Patients that received chemo/radiation therapy alone had the second highest probability of survival up to 15 months post-treatment. Patients that received a CSF/IVB flow diversion procedure (external ventricular drain, ventriculoperitoneal shunt or Ommaya reservoir) had the lowest survival probability across all post-treatment timepoints. CSF/IVB, cerebrospinal fluid/intraventricular bleeding; KMC, Kaplan Meier curves; RCC, renal cell carcinoma.