Primary meningeal tumors in children: correlation of clinical and CT findings with histologic type and prognosis.

PURPOSE To identify the radiologic features that might help in preoperative differentiation of the meningiomas from the remaining primary meningeal tumors, in particular the malignant tumors. METHODS The clinical and computed tomographic features of 21 children with histologically proved primary meningeal tumors were analyzed. FINDINGS Benign tumors (meningiomas) are more likely to occur in older children, to have longer symptom duration, and to have CT appearances similar to the "typical" adult meningioma. Atypical CT features suggest a malignant meningeal tumor, such as meningeal sarcoma, melanoma, or meningeal primitive neuroectodermal tumor. The recent identification of a new subtype of meningioma (a "sclerosing" group) is discussed. This is common in children and the CT and clinical features are similar to those seen in other meningiomas. It is frequently mistaken histologically for an intraaxial tumor, or for an atypical or malignant meningioma. These sclerosing meningiomas may also show brain invasion but despite this, in the short term, the prognosis is no different from other meningiomas. CONCLUSION The bad reputation previously ascribed to childhood primary meningeal tumors should be confined to that small group that are malignant. Meningiomas have a more favorable outlook.