Primary and secondary extracranial meningiomas of the sinonasal tract

Although meningiomas are a common type of intracranial neoplasm, extracranial meningiomas are extremely rare; they comprise 6-17% of all meningiomas. Extracranial meningiomas can arise focally, at an ectopic site (primary), or they might be extensions of intracranial lesions (secondary). Primary extracranial meningiomas appear in less than 2% of all cases. Moreover, the sites of primary extracranial meningiomas rarely include the sinonasal tract. This study describes two cases of extracranial meningiomas, one primary and one secondary, identified with histopathological tests and imaging examinations. We focused on the clinical presentation, radiographic findings, diagnostic evaluation, and treatment options of these cases. The differential diagnosis of a nasal mass should consider the possibility of an extracranial meningioma. A definitive diagnosis should be based on a histopathological diagno-sis, combined with immunohistochemistry. Imaging examinations are also used to evaluate intracranial structures, because a sinonasal meningioma can be an extension of an intracranial tumor.