Trans-Osseous Parieto-Occipital Extracranial Meningioma Under Head Scarf of Patient With Bilateral Papilledema

The incidence of meningiomas in the US is approximately 8 per 100,000 people. Extracranial meningiomas (ECMs) make up 2% of meningiomas and are subdivided into primary and, more commonly, secondary ECMs. Primary ECMs have no intracranial component. Secondary ECMs are defined as: a direct extension of an intracranial meningioma (ICM); an ECM noncontiguous with an ICM, but with the same histology; or metastatic disease. ECMs, although rare, tend to favor structures of the head and neck, including the skull base.

Poster 82 Trans-osseous Parieto-Occipital Extracranial Meningioma under Head Scarf of Patient with Bilateral Papilledema Elizabeth Akinsoji1, Sachin Kedar1, Michael Dattilo1 1 Emory University School of Medicine, Atlanta, Georgia, USA Introduction: The incidence of meningiomas in the US is approximately 8 per 100,000 people. Extracranial meningiomas (ECMs) make up 2% of meningiomas and are subdivided into primary and, more commonly, secondary ECMs. Primary ECMs have no intracranial component. Secondary ECMs are defined as: a direct extension of an intracranial meningioma (ICM); an ECM noncontiguous with an ICM, but with the same histology; or metastatic disease. ECMs, although rare, tend to favor structures of the head and neck, including the skull base. Description of Case(s): A 64-year-old Caucasian woman presented for a routine eye examination during the COVID pandemic. She denied any ocular or visual complaints. She was observed wearing a face mask, a face shield, and had her head wrapped with a head scarf. Ocular examination showed normal visual function in both eyes and bilateral, subtle edema of both optic nerves. An urgent MRI brain showed a giant extra-axial/osseous mass with trans-osseous invasion of the parieto-occipital bones; and invasion of the extracranial soft tissue throughout the parieto-occipital scalp, the superior sagittal sinus and brain parenchyma. She underwent surgical resection of the mass with adjuvant radiotherapy. Pathology revealed a WHO grade II atypical meningioma. At three month follow up, she continued to have normal visual function in each eye and her papilledema had completely resolved. Conclusions, including unique features of the case(s): We present a rare case of ECM with skull and brain parenchymal invasion associated with papilledema in an otherwise asymptomatic patient. Although WHO grade II meningiomas represent 17% of meningiomas and tend to demonstrate parenchymal invasion, there are few cases in the literature showing dual parenchymal and skull invasion associated with neuro-ophthalmic findings. Despite the extent of extracranial growth of the meningioma as seen on brain MRI, diagnosis was delayed likely by the extracranial portion of the mass being hidden by her head scarf. References: (1) Lee DH, Sim HS, Hwang JH, Kim KS, Lee SY. Extracranial Meningioma Presenting as an Eyebrow Mass. J Craniofac Surg. 2017 Jun;28(4):e305-e307. doi:10.1097/SCS.0000000000003555. (2) Buerki, R. A., Horbinski, C. M., Kruser, T., Horowitz, P. M., James, C. D., & Lukas, R. V. (2018). An overview of meningiomas. Future oncology (London, England), 14(21), 2161–2177. https://doi.org/10.2217/fon-2018-0006. (3) Wang N, Osswald M. Meningiomas: Overview and New Directions in Therapy. Semin Neurol. 2018 Feb;38(1):112-120. doi: 10.1055/s-0038-1636502. Epub 2018 Mar 16. PMID: 29548058. Keywords: tumors, neuroimaging, high intracranial pressure/headache Financial Disclosures: The authors had no disclosures. Grant Support: None. Contact Information: Elizabeth Oluwadamilola Akinsoji, [e-mail] 146 | North American Neuro-Ophthalmology Society