Meningiomas originate in the meninges and subarachnoid spaces and may be derived from dural fibroblasts or soft meningeal cells, but most originate from arachnoid cells and may occur in any site containing arachnoid components. Primary intraosseous meningioma (PIM) is a rare tumor of meningiomas that arises in the cranial bone. Primary intraosseous meningiomas are more difficult to diagnose and are characterized by osteolytic bone destruction centered on the periosteal barrier. The treatment is based on surgical resection, and complete resection of the diseased cranium is the key of reducing the recurrence rate. In this article, we reported the case of a 53-year-old man presented with an occipital mass accompanied by abnormal tendon reflexes. Magnetic resonance imaging showed an osteolytic mass in the adjacent superior sagittal sinus and sinus confluence related to the occipital bone, with extension to the cervical region. The tumor was removed except for the part that invaded the superior sagittal sinus and sinus confluence, and postoperative pathology suggested an anaplastic meningioma (WHO Grade III). Then the patient was treated with Intensity Modulated Radiation Therapy for brain lesions. We performed surgical treatment for a rare case of PIMs occurring in the occipital bone and the histopathologic diagnosis was anaplastic meningioma. This case points out that the diagnosis of primary intraosseous meningiomas should be based on the combination of imaging presentation as well as molecular pathology results, and treatment should be mainly performed by surgical resection with adjuvant radiotherapy if necessary.
Sun et al. (2026) studied this question.