Primary mediastinal malignant meningioma.

Primary ectopic meningiomas are extremely rare tumors of controversial origin and they are usually limited to the head and neck region. Its occurrence at the mediastinum is even rarer. There has not been any official report regarding primary mediastinal malignant meningioma until today. Because of its rarity and potential value, we report here a case of primary mediastinal malignant meningioma, which turns out to be the first reported case of this type of meningioma. The clinical features, treatment plans, pathological findings, as well as prognosis of a case of primary mediastinal malignant meningioma were carefully analyzed and the literature on ectopic meningioma was reviewed. The diagnosis of ectopic meningioma can only be established based on microscopic and immunohistochemical findings. Surgery is the treatment of choice for ectopic meningioma and postoperative radiotherapy should be managed for patients with suspected invasive meningioma.