Beyond the Cranium; A Case Report on the Risk Factors and Presentation of Metastatic Meningioma

Purpose: Meningiomas are the most common primary brain tumor with established risk factors including neurofibromatosis, gene mutations, ionizing radiation, and exogenous hormone use (1). Extracranial metastases are extremely rare, occurring in less than 1% of those diagnosed (2). However, cases like these have been reported in literature with some studies attempting to establish risk factors for distant disease. This report describes such a case in detail.

Methodology: A 46-year-old male presents for a range of neurologic symptoms including anosmia, decreased coordination, progressive numbness of the extremities, and painless swelling on the vertex of his head. Imaging revealed a right sided parasagittal mass with involvement of the superior sagittal sinus. He underwent resection with pathology showing WHO grade II meningioma. Adjuvant radiation and observation were discussed, and he elected for observation. After three years of observation, an MRI revealed evidence of recurrence anterior to his resection site, so he received radiosurgery at 3000 cGy in 5 fractions. At eighteen months post-radiosurgery, he developed right chest wall pain after a work accident and was found to have a right lower lobe lung nodule. Percutaneous biopsy with immunohistochemical staining was consistent with meningeal origin. Dotatate PET scan showed evidence of disease in the pleura of the right lower lobe, gastrohepatic nodes, and axial skeleton.

Results: It’s worthwhile to consider the risk of widespread metastases as illustrated by our patient. The limited existing data on the risk of extracranial metastatic meningioma suggests that the majority occur in patients with WHO grade II and III disease, and incidence seems to increase with higher grade (3). As was the case here, it appears that higher-grade disease and the presence of recurrence portend significant risk for systemic disease. Keeping these factors in mind when determining a surveillance schedule could lead to improved long-term outcomes.

Conclusions: This case highlights the rare, yet important risk factors of extracranial meningioma metastases, in cases of high-grade disease or recurrence. Traditionally considered an isolated CNS neoplasm, meningiomas have been shown to metastasize to peripheral tissues. This case report demonstrates the known risk factors for metastasis including higher grade and recurrence. This suggests the importance of controlling disease early in the treatment course. The increased recurrence risk of higher grade meningioma provides rationale for considering adjuvant radiation therapy to reduce this risk.

References: (1) Wiemels, J., Wrensch, M. & Claus, E.B. Epidemiology and etiology of meningioma. J Neurooncol 99, 307–314 (2010). https://doi.org/10.1007/s11060-010-0386-3

(2) Kessler RA, Garzon-Muvdi T, Yang W, et al. Metastatic Atypical and Anaplastic Meningioma: A Case Series and Review of the Literature. World Neurosurg. 2017;101:47-56. doi:10.1016/j.wneu.2017.01.070

(3) Dalle Ore CL, Magill ST, Yen AJ, et al. Meningioma metastases: incidence and proposed screening paradigm. J Neurosurg. 2019;132(5):1447-1455. Published 2019 Apr 5. doi:10.3171/2019.1.JNS181771