Unveiling Nasal Glial Heterotopia: A Pathological Perspective

Abstract

The uncommon, non-hereditary congenital abnormalities known as nasal glial heterotopias (NGH) are composed of heterotopic neuroglial tissue. Typically, NGH manifests in infancy, but occasionally it can also be seen in older children and adults. To rule out intracranial extension, magnetic resonance imaging (MRI) and computed tomography (CT) scans should be performed. Numerous cases have been documented where NGH was mistakenly identified as encephaloceles, teratomas, dermoid cysts, capillary haemangiomas, and even desmoids. A proper clinical, sonological, and even CT and MRI evaluation can lead to a near-final diagnosis; nonetheless, surgical excision and histological confirmation are the gold standards. We report a rare case of a firm, subcutaneous, non-tender, non-reducible midline 2 x 2 x 1 cm swelling with bluish-red skin near the root of the nose that was not affected by posture or pressure. Encephalocele, NGH, and dermoid were the differential diagnoses made based on the oedema found on CT and MRI scans. Histopathology provided a conclusive NGH diagnosis. The instance illustrates the significance of histology as the gold standard for NGH diagnosis.

Keywords: encephalocele; extranasal; intranasal; nasal glial heterotopia; nasal glioma.

Figure 1. Extra nasal mass on the left side of the root of the nose (blue box)

Figure 2. Histopathological photomicrograph showing nests and lobules of glial tissue (black arrows) (haematoxylin and eosin, 100×)

Figure 3. Histopathological photomicrograph showing glial tissue (black arrows) and fibrovascular stroma (blue arrows) (haematoxylin and eosin, 100×)

Figure 4. Histopathological photomicrograph showing astrocytes dispersed in a fine neurofibrillary matrix. Astrocytes show round to oval nuclei with the variegated appearance of cytoplasm (haematoxylin and eosin, 400×)

Black arrows showing astrocytes dispersed in a fine neurofibrillary matrix. Red arrows showing neurofibrillary matrix.

Figure 5. Post-operative site (blue box) of patient.