Extracranial Extension of a Convexity Meningioma into the Temporal Fossa: A Rare Case Report and Literature Review

TL;DR

A rare case of a meningioma growing outside the skull into the temporal fossa is reported, highlighting the need for specialized surgical approaches and close monitoring.

Contribution

This case report adds to the limited literature on extracranial extension of convexity meningiomas into the temporal fossa and emphasizes interdisciplinary collaboration.

Findings

Extracranial meningioma growth occurred over five years without intracranial progression.

Maxillofacial surgery via a preauricular approach successfully resected the tumor with preservation of the facial nerve.

Regular MRI surveillance is recommended for early detection of recurrence in such cases.

Abstract

Background and Clinical Significance: Meningiomas are among the most common primary intracranial tumors, usually benign and slow-growing. Extracranial extension is exceptionally rare, particularly when arising from convexity meningiomas extending into the temporal fossa. Such cases pose unique diagnostic and therapeutic challenges due to their atypical growth patterns and anatomical complexity. Case Presentation: A 63-year-old woman previously treated for a right temporal convexity meningioma with subtotal resection and Gamma Knife radiosurgery demonstrated progressive extracranial tumor growth over five years, while the intracranial component remained stable. MRI revealed infiltration of the temporalis and lateral pterygoid muscles and erosion of the temporal bone. Due to extensive extracranial involvement and limited neurosurgical accessibility, resection was performed by a maxillofacial surgical team through a preauricular approach. Intraoperatively, the tumor was encapsulated but adherent to the deep temporal fascia and zygomatic arch. The temporal branch of the facial nerve was identified and preserved. Histopathology confirmed a meningothelial meningioma, WHO Grade I, with low proliferative activity (Ki-67 < 1%). Postoperative recovery was uneventful, with transient facial nerve weakness that resolved within weeks. Conclusions: This report adds to the limited literature describing temporal fossa involvement by convexity meningiomas and illustrates the value of collaboration between neurosurgical and maxillofacial teams. Regular MRI surveillance every 6–12 months is advised for early detection of recurrence.

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