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A Primary Intraosseous Meningioma: A Rare Case of Malignancy with High Proliferative Ability
Yoshiki Sato1, Koichi Mitsuya1, Yuko Kakuda2
1Division of Neurosurgery, Shizuoka Cancer Center, Nagaizumi, Shizuoka, Japan.
Abstract:
Primary intraosseous meningioma (PIM) is a rare tumor that arises in the skull. Histopathologically, it is generally described as a slow-growing, benign lesion. However, on rare occasions, PIM presents as a malignancy with high proliferative ability, which requires maximal resection, adjuvant radiotherapy, and subsequent careful follow-up. Because of the rarity of such cases, they present a diagnostic challenge with unusual pathological findings. Herein, we report a case of a primary intraosseous anaplastic meningioma with extensive invasion inside and outside the skull, along with the results of whole-genome analysis. Histopathological diagnosis was a World Health Organization grade 3 anaplastic meningioma. In the literature, only two cases of anaplastic PIM have been reported, so its characteristics and treatment are poorly understood. Our patient was successfully treated with tumor resection, followed by intensity-modulated radiation therapy. Follow-up imaging studies revealed no recurrence or distant metastasis, including to lung, liver, and bone, at 8 months after the surgery.
Insights
Primary intraosseous meningioma (PIM) is a rare skull tumor. This case highlights a World Health Organization grade 3 anaplastic PIM successfully treated with surgery and radiation therapy, with no recurrence at 8 months.
Area of Science:
- Neuro-oncology
- Pathology
- Genomics
Background:
- Primary intraosseous meningioma (PIM) is a rare skull tumor, typically benign and slow-growing.
- Malignant PIM, though exceptionally rare, presents diagnostic and therapeutic challenges due to aggressive behavior and unusual pathology.
- Understanding the characteristics and treatment of anaplastic PIM is crucial due to its rarity.
Observation:
- A case of primary intraosseous anaplastic meningioma (WHO grade 3) with extensive skull invasion is presented.
- The tumor exhibited high proliferative activity and unusual pathological findings, posing a diagnostic challenge.
- Whole-genome analysis was performed to investigate the genetic underpinnings of this rare malignancy.
Findings:
- The patient underwent maximal tumor resection followed by intensity-modulated radiation therapy.
- Histopathological diagnosis confirmed a World Health Organization grade 3 anaplastic meningioma.
- Literature review revealed only two previously reported cases of anaplastic PIM.
Implications:
- This case contributes to the limited understanding of anaplastic PIM characteristics and management.
- Successful treatment with surgery and adjuvant radiotherapy suggests a viable therapeutic strategy.
- The findings underscore the importance of thorough follow-up for aggressive PIM cases to monitor for recurrence or metastasis.
