Introduction: Nasopharyngeal cerebral heterotopia and encephalocele are rare congenital benign masses of neurogenic origin. Encephalocele develops when brain tissue and overlying meninges herniate out through a cranial defect. In contrast to encephalocele, which shows direct connection to the brain, cerebral heterotopia is defined as an extracranial brain tissue not connected to the brain. Heterotopic brain tissue is an extremely rare lesion, most frequently located in the nasal cavity. However, it can be located in the orbit, oral cavity, scalp, pterygopalatine fossa, middle ear, neck, and pharynx.
Here, we report an atypical presentation of nasopharyngeal cerebral heterotopia in a 4-day-old newborn.
Case description: A 4-day-old full-term newborn was referred to our center due to feeding difficulties and obstructed nasal respiration alleviated during prone position. Shortly after delivery he developed respiratory distress, which significantly improved following nasal airway and nasogastric tube placement. Fiber optic endoscopy evaluation performed at 5 days of age revealed a nasopharyngeal mass obstructing the upper respiratory airways. Furthermore, a focused cervical sonography demonstrated a cystic fluid-filled lesion with a few thin septae, separated from the tongue base. MRI performed at 6 days of age showed a large, well-defined, partially cystic lesion measuring 1.2x1.3x3.2 cm (length, width, and depth respectively), located in the nasopharynx, at midline and not connected to the brain. Neither brain MRI scans nor cranial sonography revealed any intracranial abnormality. Subsequently, surgical exploration revealed a grayish partially solid (cheese-like) mass, with clear fluid component, extending from the nasopharyngeal roof caudally to the soft palate. The mass was surgically resected and sent to pathology, without any CSF leak noticed during surgery. Eventually, histologic analysis of the resected specimen demonstrated mature neuroglial tissue with positive immunohistochemical expression of glial fibrillary acidic protein (GFAP), thus consistent with nasopharyngeal cerebral heterotopia.
Discussion and summary: Cerebral heterotopia is a rare congenital benign mass, most frequently reported in the nasal cavity and presenting with respiratory distress due to upper airway obstruction and swallowing difficulties. Imaging plays a key role in differentiating this condition from encephalocele that has intracranial attachment, and requires a different surgical approach in-order to prevent CSF leak. Familiarity with the imaging features of cerebral heterotopia is essential for better patients’ care.
