Malignant primary intraosseous meningioma in a pediatric patient: A case report and review

Introduction: This is the first case of a malignant, pediatric PIOM reported in the United States. Primary extradural meningiomas (PEM) arise in locations other than dura, outside the intracranial compartment. Primary Intraosseous Meningiomas (PIOMs) are a rare subset of PEM that arise in bone. Case report: A 16 year old female, neurologically intact, mildly tender swelling over her right forehead that increased in size, accompanied by headaches and dizziness. Imaging demonstrated a lesion infiltrating the frontal calvarium and the adjacent intracranial and extracranial soft tissues. Surgical resection was performed. Pathology supported the diagnosis of anaplastic meningioma (WHO grade III). Discussion: PIOMs are a rare subset arising in bone. In an extensive review, less than 150 cases of PIOMs were found. It likely originates from entrapment of arachnoid cap cells, congenitally or after development. Treatment is similar to intradural meningiomas, namely a potentially curative resection. Resection and cranioplasty should be performed simultaneously. Adjuvant radiation, chemotherapy and bisphosphonates are recommended.