A 57-year-old female presented with sudden onset of loss of taste and tongue deviation to the left on protrusion. She had slurring of speech but no limb weakness, no syncopal attack, no headache, no vomiting, and no history of seizure. Underlying medical problems revealed that she suffered from hypertension, psoriasis, and right knee osteoarthritis. She was first seen by the neurosurgery team as the computed tomography (CT) scan showed right posterior frontal-subcortical intraparenchymal bleed with multifocal infarcts. A magnetic resonance imaging (MRI) was also performed and there was an incidental finding of right masticator space lesion following the course of the right mandibular nerve. The patient was then referred to us for further management.
On examination, her face was symmetrical. She had slurred speech, tongue deviation to the left but no paresthesia of her tongue or right labiomental region. There was no buccal or lingual bony expansion at the right mandible. However, thick fibrous mucosa was palpable lingually.
The panoramic radiograph showed enlarged well-defined radiolucency zone of the right mandibular canal measuring 8.6 mm compared to the left side which measures 2.3 mm. There was also loss of cortication of the mandibular canal [Figure 1].
Cone-beam CT (CBCT) confirmed the above radiological findings with intact, uninterrupted cortication of the mandibular canal only at the superior border [Figure 2].
The MRI scan showed well-defined T1-hypointense and T2-hyperintense lesion at the right masticator space invaginating into the right mandibular canal measuring 2.6 cm x 1.7 cm x 3.4 cm (AP x W x L) [Figure 3]. It had minimal central enhancement seen postcontrast. No evidence of intracranial perineural spread.
Impression of the lesion radiographically was either schwannoma or neuroma. The patient declined incisional biopsy to establish the diagnosis of the lesion as she was asymptomatic and unwilling to take the risk of paresthesia postbiopsy.