Malignant meningioma: clinical and pathological features

Area of Science:

• Neuropathology
• Oncology

Background:

• Meningiomas are tumors arising from the meninges.
• Malignant meningiomas represent a rare and aggressive subset with significant morbidity and mortality.

Purpose of the Study:

• To review and classify meningioma cases based on histological features.
• To evaluate the clinical course, prognosis, and risk factors associated with malignant meningiomas.

Main Methods:

• Retrospective review of 15 patient records with a diagnosis of malignant meningioma.
• Histopathological analysis including mitotic count, architectural assessment, and presence of necrosis and invasion.
• Correlation of histological findings with clinical outcomes, including recurrence, metastasis, and survival.

Main Results:

• One case initially diagnosed as malignant was reclassified as benign.
• Seven tumors were borderline-malignant, showing invasion but few mitoses; outcomes varied, with some deaths from recurrence.
• Seven tumors were histologically frankly malignant, characterized by anaplasia and numerous mitoses; most patients died, with three from metastases.
• Malignant meningiomas have a short clinical course, high recurrence rates, and potential for extracranial metastases.
• Hemangiopericytomas were common among malignant types, and men were identified as a high-risk group.

Conclusions:

• Histological grading is crucial for determining prognosis in meningiomas.
• Malignant meningiomas, particularly hemangiopericytomas, present a poor prognosis with a high likelihood of recurrence and metastasis.
• Early recognition and aggressive management are essential for improving outcomes in patients with malignant meningiomas.