UNASSIGNED: Meningiomas are slow-growing neoplasms, accounting for 20% of all primary intracranial neoplasms and 25% of all intraspinal tumors. Atypical and anaplastic meningiomas are infrequent, representing fewer than 5% of all meningiomas. Unusually, they can show aggressive behavior, and extracranial metastases are extremely rare, representing approximately 0.1% of all reported cases.
UNASSIGNED: Fifty-six-year-old male patient diagnosed with atypical basal frontal meningioma with multiple resections, both endoscopic endonasal and transcranial. After hypofractionated radiosurgery, the patient showed new tumor recurrence associated to right cervical level II ganglionic metastasis. We opted for complete resection of the meningioma and reconstruction with anterior rectus abdominis muscle flap, as well as selective cervical ganglionectomy. Anatomical pathology showed neoplastic proliferation of meningothelial cells in syncytial cytoplasm, oval or spherical nuclei with slight anisocariosis and hyperchromasia, and intranuclear vacuoles, all compatible with anaplastic meningioma.
UNASSIGNED: Due to a lack of consensus on how to treat a metastatic malignant meningioma, this pathology requires a multidisciplinary approach, and treatment needs to be adapted to each particular case. Complete resection of the lesion is the primary goal, and this requires complex procedures involving endocranial as well as extracranial surgeries, which result in composite defects difficult to resolve. Microvascular free flaps are considered the gold standard in reconstructions of large skull base defects, with high success rates and few complications.

BACKGROUND: Meningioma is the most common type of benign primary brain tumor that is rarely associated with distant metastasis. No established treatment strategy for metastatic meningiomas exists to date. Herein, we report a case of solitary pulmonary metastasis of meningioma detected 2 years after neurosurgical resection of the primary tumor.
METHODS: A 75-year-old male patient underwent neurosurgical resection of a convexity meningioma (World Health Organization grade II atypical meningioma), followed by postoperative radiotherapy for the residual tumor. Two postoperative years later, a solitary 10-mm pulmonary nodule in the left lower lung lobe was detected on chest computed tomography. The patient underwent video-assisted thoracoscopic left lower lobectomy for suspected pulmonary metastasis of meningioma. The pathological diagnosis was solitary pulmonary metastasis of meningioma. No sign of further recurrence was noted at 8 months postoperatively.
CONCLUSIONS: We present a rare and unique surgical case of solitary pulmonary metastasis of meningioma. Further investigation is necessary to establish the standardized treatment strategy for metastatic meningiomas.

Although meningiomas are the most common central nervous system neoplasms, extracranial metastases are exceedingly rare. There are even fewer reports of metastatic meningiomas to the neck.
We described a patient with multiply recurrent orbital meningioma with metastasis to the neck found incidentally during neck exploration for composite resection and free tissue reconstruction. We performed a systematic review for all records pertaining to metastatic meningiomas to the cervical regions.
We found 9 previous reports of cervical metastatic meningiomas. Almost all cases underwent extensive local resection. There was no evidence of an association between the histological grade of the tumor and risk of metastasis to the neck. Cervical lymph node dissemination is more common in patients presenting after previous primary tumor resection.
In the context of a neck mass, our findings suggest that metastatic meningioma should be included in the differential diagnosis, especially in patients with previous resections.

To identify genes altered in a highly aggressive metastatic meningioma primary as well as its metastases. Exome sequencing of a primary anaplastic meningioma and metastatic lesions in which DNA could be extracted and compared to germline DNA. Genetic analysis of the metastatic sites found 31 common mutations among the primary tumor and two metastatic sites. Additionally, genetic mutations were identified which were either infrequently (MUC3A, ALDH1A3, HOXA1) or not at all previously described in meningiomas (CASS4, CMKLR1). Exome sequencing of a metastatic meningioma and its distant metastases outside the CNS identified mutations that were not previously well described.

Meningiomas are common intracranial tumors that rarely metastasize. We present a highly unusual case of a 42-year-old man with direct seeding of meningioma to the abdominal wall. The patient had a history of multiple operations for a recurrent intracranial meningioma with decompressive craniectomy and preservation of the calvarial bone flap by implantation into the subcutaneous layer of the anterior abdominal wall. Following removal of the bone flap, a new abdominal wall mass was identified, consistent with iatrogenic implantation of anaplastic meningioma.

Meningioma represents the most frequently diagnosed primary brain tumor, accounting for over one-third of central nervous system neoplasms. The majority of tumors are categorized as benign. However, albeit rarely, meningiomas may metastasize to distant sites. We describe a 78-year-old man with a history of recurrent World Health Organization grade I meningioma managed who presented for evaluation of weakness and urinary retention. A computed tomography scan obtained in the emergency department revealed multiple scattered low-density liver lesions. Subsequent magnetic resonance imaging showed a 5.5-centimeter heterogeneous enhancing mass with 2 smaller enhancing lesions suspicious for a primary or secondary malignant neoplasm. Microscopic examination of a tissue sample obtained via liver biopsy demonstrated a metastatic spindle cell neoplasm with histologic features compatible with a diagnosis of World Health Organization grade I transitional meningioma. The patient was referred to hematology/oncology for systemic therapy.

BACKGROUND: Metastatic meningiomas (MMs) are rare (0.1 of 100 cases). Their 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. In this study, the authors performed a review of the literature and reported 2 cases of patients affected by extracranial MMs, with long-term follow-up.
METHODS: Case 1: A 48-year-old woman was admitted for resection of an extra-axial falx lesion (meningioma G1). After 2 years, the lesion got a local recurrence, resected with a histologic diagnosis of meningioma G3. During the next 9 years, the patient underwent 5 Gamma Knife radiosurgery (GKRS) procedures for local recurrence. At 56 years, she was readmitted for a surgical local recurrence (histologic definition: anaplastic meningioma G3). At the age of 62, the patient underwent a right lobectomy for a lung mass (histologic diagnosis: anaplastic meningioma G3). After that, multiple lesions at soma L5 and adrenal gland were discovered and then monitored. Case 2: A 48-year-old woman was operated for a lesion involving torcular herophili (meningioma G2). After 3 years, a local recurrence requires GKRS combined with tamoxifen. In the next 7 years, she underwent 5 GKRS procedures for local recurrence. The patient also underwent chemotherapy with octreotide. At the age of 61, she discovered multiple lesions in both lungs, liver, and kidney. A hepatic biopsy showed anaplastic meningioma G3. Also this patient does not suffer from any neurologic or clinical deficits.
CONCLUSIONS: LC in malignant meningioma is achievable through a multimodal approach; GKRS makes possible LC, but a novel aspect of these lesions is opened to discussion: the metastases. These reports show 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 is involved.

UNASSIGNED: Extracranial metastasis from intracranial meningioma is a very rare condition. A current literature review reveals that only few cases are documented with extensive pulmonary involvement >10 years after initial intracranial meningioma resection. Diagnosis of pulmonary meningioma is often confirmed by computed tomography chest-guided core biopsies. The prognosis of extensive metastatic pulmonary meningioma, however, is unknown and there is no gold standard treatment option.
UNASSIGNED: We present a case of multiple pulmonary meningioma metastases developing 13 years after initial resection of left occipital parafalcine World Health Organization Grade I intracranial meningioma.
UNASSIGNED: There are no established guidelines for the optimal management or surveillance of extensive pulmonary metastatic meningioma. In patients with high-grade meningioma and multiple cannonball pulmonary lesions, metastatic meningioma should be considered as part of the differential diagnosis. Metastatic meningioma may occur even a decade after initial tumour resection.

BACKGROUND: Malignant meningiomas are rare neoplasms of the central nervous system that occur de novo or rarely as a result of transformation. They have a higher rate of recurrence and metastasis accompanied by a significantly shorter survivorship compared with benign variants. Meningioma cancer stem cells (CSCs) have been previously shown to be associated with resistance and aggressiveness. However, the role they play in meningioma progression is still being investigated.
METHODS: We report a 29-year-old man who underwent a resection of a grade I meningioma in 2011. The patient had multiple local recurrences of the tumor that showed an aggressive change in behavior and transformation to grade III meningioma, and developed extracranial metastasis to the cervical spine. He underwent multiple operations and received radiotherapy. Analysis of the tissues indicated the presence of CSC markers before metastasis, and showed increased expressions of associated markers in the metastasized tissue. In addition, similar to the patient\'s profile, the pharmacological testing of a primary cell line retrieved from the metastasized tissues showed a high level of drug tolerance and a diminished ability to initiate apoptosis.
CONCLUSIONS: Malignant progression of grade I meningioma can occur, and its eventuality may be anticipated by detecting CSCs. We performed a comprehensive literature review of relevant cases and discussed the clinical, diagnostic, and management characteristics of the reported cases.

Anaplastic meningioma is seldom encountered. Moreover, distant metastasis is extremely rare, with only a handful cases reported. Here, we report the case of a 74-year-old female patient who underwent a combined cranial and endonasal approach for an extensive spheno-orbital anaplastic meningioma (WHO grade III), followed by adjuvant radiotherapy. Although local tumor control was achieved, she presented with lung metastasis 2 years later. The patient then died from pulmonary complications related to chest metastasis. On the basis of this case, we discuss the available literature on metastatic meningiomas and radiologic follow-up strategies.