A neuro-oncologic challenge: the case of a large, aggressive, malignant meningioma of the skull base with paranasal sinus involvement.

BACKGROUND: Malignant meningiomas, rare tumors that account for approximately 1%-3% of all meningioma, have high recurrence, morbidity, and mortality rate and a particularly poor outcome. Surgical excision followed by adjuvant radiotherapy is the current approach for the treatment of these tumors. METHODS: In the case reported, the disease, characterized by a high proliferative index (Ki67 60%-70%), was treated with endoscopic surgery limited to the extracranial portion; then the patient underwent radiotherapy, on the residual tumor volume, to a total dose of 66 Gy delivered in 33 fractions (2 Gy/fraction) by helical intensity-modulated radiation therapy with image-guided radiotherapy daily checks (tomotherapy). RESULTS: Two and a half years after the treatment, the patient is alive and a partial response is maintained. The patient is healthy overall with grade I fatigue and grade II hearing loss as late toxicity (Common Terminology Criteria for Adverse Events 4.1). CONCLUSIONS: Within a multidisciplinary approach, new radiotherapy techniques confirm their effectiveness and reliability for the treatment of malignant meningioma.