Massive mature cystic teratoma of the head and neck, masquerading as a glial choristoma, causing respiratory compromise of a neonate

Correspondence to Dr Timothy Els; [email protected]

Background

Congenital masses of the deep neck spaces and oral cavity are rare and usually benign in nature but may potentially cause life threatening upper airway obstruction.^{1 2} The broad differential for masses in this region includes cysts, pseudocysts (including ranulas), neoplasms, inflammatory conditions and infections.^1–3 Making an accurate diagnosis can be challenging due to the broad differential, as well as the potential risk of airway compromise. This is particularly problematic for both imaging (where a child may require sedation) and histological diagnosis (where sedation, anaesthesia and potential bleeding are all risks for airway compromise).

A choristoma is a congenital heterotopic mass of microscopically normal cells, occurring in an abnormal location.¹ These occur mainly in the head and neck region,⁴ and may contain heterotopic gastric mucosa, neural tissue, cartilage, bone or epithelium.¹ Glial choristoma refers to ectopic central nervous tissue, embryologically linked to an encephalocele, although it is not continuous with the brain.⁵ According to the literature, the most commonly occurring glial choristoma is a nasal glioma, with the parapharyngeal space and oral cavity being extremely rarely involved.^{4 6} Within the oral cavity and parapharyngeal space, lesions most frequently affect the palatopharyngeal area, followed by the tongue, oropharynx, upper lip and submandibular area.^4–7

A teratoma involving the oropharynx is a rare benign congenital growth comprising cells from all three germ layers.^{8 9} Overall incidence is 1 in 4000 live births, with only 2% involving the oral cavity and oropharynx (1 in 35 000–200 000 000 live births).⁹ These may be associated with other congenital malformations in up to 6% cases, with cleft palate most commonly seen.⁹ In this case report, we present a neonate born with a large parapharyngeal and oral cavity mass, diagnosed on three histological samples as a glial choristoma which resulted in upper airway compromise requiring surgical intervention. We will discuss the histological findings, work-up and treatment of this patient with the aim of supplementing the limited existing clinical knowledge of this congenital anomaly and understanding the implications of a paediatric tracheostomy in our setting.

Case presentation

A female neonate was born via normal vertex delivery to a mother in her 20s in the Eastern...