Nasal Glial Heterotopia in a 1-Year-Old Child – A Case Report: Histopathology is the Ultimate Gold Standard for Diagnosis!!

Abstract

Nasal glial heterotopia (NGH) is a benign congenital malformation wherein abnormally located mature brain (glial) tissue presents as a mass on the forehead or nasal root area. Rarity of this condition makes clinical level diagnosis a challenge. Differential diagnoses for NGH are dermoid cyst, encephalocoele, hemangioma, allergic nasal polyp, or chronic otitis media. NGH has no direct communication with intracranial cavity, unlike an encephalocoele. However, potential intracranial connection is possible, through cribriform plate or bony deformities. Therefore, pre-operative aspiration and biopsies are contraindicated in childhood swellings in forehead/nasal bridge area. Instead, pre-operative imaging modality investigations are mandatory. It is also important to note the risk for the removal of functional brain tissue and also post-operative meningitis or cerebrospinal fluid rhinorrhea. A 1-year-old female child presented with a mass on nasal bridge. Overlying skin was unremarkable. Swelling did not increase in size on coughing. Diagnosis: Dermoid cyst/encephalocoele. Computed tomography (CT) scan investigation: CT scan confirmed the diagnosis of nasal encephalocoele > nasal dermoid. The mass was excised. Histopathology (histopathological examination [HPE]): The excised specimen was a single, unencapsulated, ovoid, and soft to firm, yellow-colored tissue bit, measuring 2.5 cm × 2 cm × 1 cm. On cut section, there were no cystic areas/spongy appearance/mucoid bits. Hematoxylin and eosin-stained sections revealed a poorly circumscribed mass, showing a population of cells with ovoid or irregular nuclei and a fibrillary stroma – resembling cerebral and glial tissue. These were arranged in a disorganized fashion and were surrounded by fibrous tissue and few skeletal muscle fibers. All HPE findings point toward the diagnosis of NGH. It is important to consider NGH as a differential, in case of childhood swellings in the forehead and nasal root region. Histopathology remains the gold standard for diagnosis.