Nasal gliomas: identification and differentiation from hemangiomas.

Nasal gliomas are rare congenital midline tumors composed of heterotopic neuroglial tissue. The differential diagnosis of a nasal glioma includes neurogenic tumors, ectodermal tumors, mesodermal tumors, and teratomas. Initial evaluation of a nasal glioma should include skull radiographs and either a CT or MRI scan to rule out intracranial extension. CT or MRI scans can be used, but MRI scans are preferable due to their superior soft tissue enhancement. There have been several cases reported in which nasal gliomas were misdiagnosed as capillary hemangiomas. In cases in which clinical uncertainty exists, ultrasound and Doppler flow studies can be performed to noninvasively differentiate nasal gliomas from capillary hemangiomas. Ultrasound is useful for determining if the mass is cystic or solid. Doppler flow studies of nasal gliomas reveal a characteristic low arterial flow velocity during the end-diastolic phase. Microscopic and immunohistologic studies provide definitive confirmation of a nasal glioma. Once the diagnosis of a nasal glioma is established, early surgical resection is advocated to prevent local recurrence, nasal deformity, and secondary visual involvement.