A nasal glioma is a rare, non-cancerous mass present from birth, appearing on or inside the nose. Despite its name, it is not a true brain tumor or a malignant growth. This congenital lesion consists of normal glial tissue, supportive cells found in the brain and spinal cord, displaced outside the skull during fetal development. This displacement occurs when neuroectodermal and ectodermal tissues fail to separate properly during the nose’s embryonic development. The term “nasal glial heterotopia” is often used to describe this non-neoplastic condition, emphasizing it as misplaced brain cells.
Symptoms and Types of Nasal Gliomas
Nasal gliomas present as a firm, non-compressible, non-pulsatile mass, located on or near the bridge of the nose. This differentiates them from encephaloceles, which are often soft and may exhibit pulsation due to a direct connection to the brain’s fluid-filled spaces. Nasal gliomas are slow-growing.
They are classified into three types by location. Extranasal gliomas, accounting for about 60% of cases, appear as a visible lump on the outside of the nose. Intranasal gliomas, making up about 30% of cases, are located inside the nasal cavity, potentially leading to symptoms such as nasal obstruction, breathing difficulties in infants, or a deviated septum. The remaining 10% are mixed forms, with both external and internal components.
The Diagnostic Evaluation
Diagnosis of a nasal glioma relies on imaging studies. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are the primary tools to visualize the mass. MRI is preferred due to its superior soft tissue definition, allowing detailed visualization of the lesion and surrounding structures.
A primary goal of these scans is to rule out any connection to the brain, known as intracranial extension. While a fibrous stalk connecting the glioma to intracranial structures can be present in up to 15-20% of cases, it does not contain a direct fluid-filled tract communicating with the subarachnoid spaces, distinguishing it from an encephalocele.
Although imaging provides a strong presumptive diagnosis, the definitive diagnosis is made through histopathology. This involves a microscopic examination of the tissue by a pathologist, revealing mature glial cells interwoven with fibrovascular connective tissue.
Surgical Management
Complete surgical excision is the standard treatment for a nasal glioma. The main objectives are to remove the entire mass to prevent recurrence and achieve a favorable cosmetic outcome. Early intervention is recommended, particularly for intranasal gliomas that might cause respiratory obstruction in infants.
The specific surgical approach depends on the glioma’s size, location, and any intracranial connection. Extranasal lesions may be removed through an external incision. Intranasal or mixed lesions without intracranial extension can be managed with a minimally invasive endoscopic transnasal approach, offering good visualization and reduced trauma. If imaging indicates an intracranial connection, a multidisciplinary team will determine the safest approach, which might involve a combined intracranial and extracranial procedure.
Prognosis and Long-Term Outlook
With complete surgical removal, the prognosis for individuals with nasal gliomas is excellent. These masses are benign. The recurrence rate following complete excision is very low, ranging from 4% to 10%.
Post-operative care focuses on monitoring the surgical site for proper healing and addressing any cosmetic concerns. Since nasal gliomas are benign, additional treatments like chemotherapy or radiation therapy are not needed. Patients experience a full recovery with minimal long-term issues when the mass is entirely removed.