Surgical Challenges of Meningiomas with Extracranial Invasion: A Clinical Study

Objective: Meningiomas are mostly benign tumors located intracranially and intradurally, but they can rarely show extradural and extracranial growth. Surgical treatment of extracranial meningiomas is specifically challenging. In this study, we present an illustrated surgical series to convey our experience in treating meningiomas with extracranial extension. Methods: We retrospectively reviewed 11 patients with meningioma who underwent surgery between 2008 and 2020. In these patients, both intracranial and extracranial components were confirmed both radiologically and intraoperatively. Results: The patients were 7 males and 4 females with a mean age of 55.4 years. Most presented with facial disfigurement or asymmetrical growth of their skull. The most common symptom at presentation was headache. The most common location of meningiomas was the frontal region and that of extracranial growth was the paranasal sinuses and parietal bone invasion. We recognized two distinct modalities of bone destruction: hyperostosis (n=3) and osteolysis (n=8). Pathological study revealed atypical features in 6 patients. Preop embolization was attempted in 4 patients and proved difficult. Proper embolization was achieved only in one patient. The most commonly encountered surgical challenges were large calvarial and cranial base defects due to bone erosion, dural defects, and managing the superior sagittal sinus with parietal tumors. Excessive blood was of a particular concern and was managed by simple scalp clips, intraoperative transfusion, and conservative approach for tumor extensions into paranasal sinuses. No perioperative mortality occurred. Postoperative CSF fistulas beneath the scalp were common complications but conservatively managed with pressure wrapping. No cranial base CSF fistula developed. Calvarial reconstruction was performed with PMMA cement where needed. Conclusions: Meningiomas with extracranial extension are surgically challenging but treatable tumors. It contains fine neurosurgical trics in its treatment and follow-up.