Distant metastases in meningioma: an underestimated problem

Area of Science:

• Neuro-oncology
• Pathology
• Oncology

Background:

• Meningiomas are common intracranial tumors originating from meningothelial cells.
• While generally benign, malignant behavior including distant metastases can occur.
• Understanding metastatic patterns and clinical presentation is crucial for patient management.

Purpose of the Study:

• To analyze the metastatic pattern of meningiomas, considering tumor grade.
• To identify clinical signs associated with distant meningioma metastases.
• To assess the prevalence and characteristics of metastatic meningioma cases.

Main Methods:

• Systematic review of PubMed database for distant meningioma metastases (1990-2012).
• Inclusion of 115 cases with 164 metastatic lesions.
• Analysis of tumor grade, metastatic site, size, and clinical presentation.

Main Results:

• Metastases were most frequent in the lung (37.2%), bones (16.5%), and intraspinally (15.2%).
• Tumor grade distribution: 33.9% grade 1, 20.9% grade 2, 40% grade 3.
• 50.4% of metastases were clinically manifest, 31.3% incidental, and 18.3% asymptomatic; 31.3% were clinically silent.

Conclusions:

• Meningioma metastasis, though rare, occurs and predominantly affects the lungs and bones.
• A substantial proportion of metastatic meningiomas are clinically silent, potentially leading to underdiagnosis.
• Metastatic patterns do not significantly differ by tumor grade, but higher grades are more common in metastatic cases.