Case Report
An 11-year-old female presented with an asymptomatic, right neck mass
first noted 7 months prior. Physical examination was notable for a large
right parapharyngeal space mass on palpation of the oropharynx and neck,
with medialization of the right oropharynx. Atrophy and fasciculations
of the right side of the tongue were seen, consistent with a right
hypoglossal nerve paralysis. Flexible fiberoptic laryngoscopy
demonstrated effacement of the right nasopharynx and oropharynx, with
preserved vocal fold function. All other cranial nerves were intact.
Magnetic resonance imaging (MRI) of the neck highlighted a large ovoid
mass in the right parapharyngeal space measuring 4.9cm x 3.7cm x 7.4cm.
The tumor extended from the jugular foramen superiorly to the level of
C5 inferiorly, but without intracranial extension. The mass caused acute
displacement of the internal and external carotid arteries anteriorly,
and compression of the internal jugular vein postero-laterally.
T2-weighted MRI sequences demonstrated heterogeneous hyperintensity
(Figures 1A and 1B). T1-weighted MRI sequences showed a hypointense
lesion with homogeneous avid enhancement after administration of
gadolinium-based contrast, consistent with schwannoma (Figure
1C).1 Genetic testing and Pediatric Brain and Nervous
System Tumor Panel (Invitae; San Francisco, California) were negative
for any germline mutations. Following multi-disciplinary review and
extensive patient and family discussion, the decision was made to
proceed with complete surgical excision, involving a combined
transcervical-mandibulotomy approach (Figures 2A-2E).
Histopathologic examination of the tumor confirmed schwannoma with
immunohistochemistry showing diffuse S100 and focal SMA positivity.
Memorial Sloan Kettering Integrated Mutation Profiling of Actionable
Cancer Targets (MSK-IMPACT), a next-generation sequencing assay of all
protein-coding exons of 468 cancer genes, demonstrated TET1deletion of exons 1 and 2.
The patient underwent an uncomplicated post-operative recovery. A
temporary gastrostomy tube was sited to assist with nutritional
supplementation during swallow rehabilitation. A right vocal fold
injection augmentation with Prolaryn Plus (Merz Pharma GmbH & Co. KGaA;
Frankfurt, Germany) was performed with a good voice result. At 3 months
post-operation, the patient had no significant dysphagia or aspiration
and demonstrated a normal voice.