Parapharyngeal space neuroglial heterotopia with tumoral differentiation

Introduction: Neuroglial heterotopia is a rare condition in which mature neuroglial tissue is found in the body other than in the central nervous system. Nasal glioma is neuroglial heterotopia in the nasal cavity. We report an extremely rare case of heterotopic neuroglial tissue in the temporal bone with tumoral transformation. Case report: Our patient was a 1-year-old Chinese girl. She was born with a left facial swelling. CT and MRI revealed a heterogeneous mass with cystic component occupying the parapharyngeal space. The upper airway was significantly compromised by the mass which extended into the middle cranial fossa. A combined approach to its resection was undertaken by ENT and neurosurgeons which was uneventful with all cranial nerves in its vicinity preserved. Intraoperative findings confirmed the absence of direct communication between the mass and the brain. Pathological examination confirmed mature neural tissue with tumoral differentiation. Conclusion: Heterotopic neuroglial tissue is a rare condition in the temporal bone. Ganglioglioma formation within the heterotopic neuroglial tissue is an even rarer condition. Careful pre-operative investigations and planning is the key to successful and complete excision of the abnormal tissue whilst preserving normal function.