A series of parapharyngeal glial heterotopia mimicking lymphatic malformation

Otolaryngologists will most frequently encounter extra-cranial glial tissue within the nasal cavity, where it is known as a 'nasal glioma', and may communicate with the dura. However, glial tissue can also present extra-nasally in the form of a neck mass with no intracranial connection. In these rare cases, they can present soon after birth as an enlarging neck mass, causing compressive symptoms with airway obstruction and feeding difficulties. In this way, it is often initially misdiagnosed as a more common lesion such as a lymphatic malformation, teratoma, branchial anomaly or vascular malformation. As with many congenital head and neck masses, offering the most the appropriate management relies heavily on radiological imaging and, where possible, histopathology from a diagnostic biopsy. Once the diagnosis of extra-nasal glial heterotopia has been confirmed, the gold standard management is complete surgical excision. We review three cases of extra-nasal glial heterotopia presenting to our institution over an eleven year period as a large neck mass, which mimicked other congenital neck lumps, and discuss them in the context of those in the literature. We highlight how their clinical and radiological features can easily be confused with lymphatic malformations, and the potential implications of misdiagnosis. Raising awareness of this diagnostic confusion will highlight the need for management of these cases within an appropriate paediatric multidisciplinary setting.