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Published on: July 5, 2021
[A case of intraosseous meningioma with extracranial progression having difficulty in making a preoperative
Masataka Nanto1, Naoki Tsuji, Junichiro Miki
1Department of Neurological Surgery, Wakayama Medical University, Japan.
Abstract:
Intraosseous meningioma is very rare and is often confused preoperatively with a primary bone tumor of the skull. We report a case of intraosseous meningioma with hyperostosis for which preoperative diagnosis was difficult. A 78-year-old female with a slowly growing hard mass in the left parietal bone was admitted. Neurological findings were normal. Plain skull radiograph showed a 6 x 6 cm hyperostotic lesion in the left parietal bone. Bone window CT scan showed thickening and hyperostosis in the same area. MRI using Gd-DTPA showed heterogeneous enhancement of the intraosseous mass, and homogenous enhancement of the dura matter. And angiogram showed a tumor stain fed by the bilateral superficial temporal artery and the It-occipital artery. The tumor and the underlying dura mater were totally removed. Preoperative diagnosis was an osteogenic tumor, but histological examination revealed a transitional meningioma. We discussed the development and the classification of an ectopic meningioma and the mechanism of hyperostosis. We should be aware of the existence of intraosseous menigiomas mimicking osteogenic tumors.
Insights
Intraosseous meningioma, a rare skull tumor, can mimic primary bone tumors. This case highlights the diagnostic challenges and emphasizes awareness of these ectopic meningiomas.
Area of Science:
- Neurosurgery
- Oncology
- Radiology
Background:
- Intraosseous meningiomas are rare tumors arising from ectopic meningothelial cells within the skull bone.
- They are often misdiagnosed preoperatively as primary bone tumors, leading to diagnostic challenges.
Observation:
- A 78-year-old female presented with a slowly growing, hard mass in the left parietal bone.
- Radiography revealed a 6x6 cm hyperostotic lesion; CT showed thickening and hyperostosis; MRI demonstrated heterogeneous enhancement; angiography indicated tumor vascularity from superficial temporal and occipital arteries.
Findings:
- Histological examination confirmed a transitional meningioma, despite preoperative suspicion of an osteogenic tumor.
- The tumor involved significant hyperostosis of the parietal bone.
Implications:
- This case underscores the importance of considering intraosseous meningioma in the differential diagnosis of skull hyperostotic lesions.
- Increased awareness and advanced imaging are crucial for accurate preoperative diagnosis and appropriate surgical planning of ectopic meningiomas.
