Multimodal management of metastatic malignant meningiomas: the role of radiosurgery in long-term local control

Abstract Metastatic meningiomas (MMs) is rare (0.1/100 cases). Treatment requires a multimodal approach, with surgery, radiotherapy, chemotherapy and radiosurgery, which allows a long-term local control (LC) and an extension of free survival (PFS). In this study, the authors performed a review of the literature and reported two cases of patients affected by extracranial MMs, with long-term follow-up. Case 1 a 48 yo woman was admitted for resection of an extra-axial falx lesion (meningioma G1). After two years, the lesion got a local recurrence, resected with a histological diagnosis of meningioma G3. During the following 9 years, the patient underwent 5 times GKRS for local recurrence. At 56 yo, she was readmitted for a surgical local recurrence (histological definition: anaplastic meningioma G3). At age 62 yo, the patient underwent to right lobectomy for a lung mass (histological diagnosis: anaplastic meningioma G3). After that, multiple lesions at soma L5 and adrenal gland were discovered and then monitored. Case 2 a 48 yo woman was operated for a lesion involving torcular Erophilii (meningioma G2). After three years, a local recurrence requires GKRS combined with Tamoxifene. In the next seven years, she underwent 5 GKRS for local recurrence. The patient also carried out chemotherapy with Octeotride. At age 61 yo, she discovered multiple lesions in both lungs, liver, kidney. A n hepatic biopsy showed anaplastic meningioma G3. Also this patient does not suffer s from any neurological neither clinical deficits. LC in malignant meningioma is achievable through a multimodal approach; GKRS make possible LC but a novel aspect of these lesions is opened to discussion: the metastases. Those reports shows that multimodal treatment for MMs is an effective approach with good LC and improvement of overall survival. However a long survival may allow systemic diffusion of the disease in particular when sagittal sinus are involved.