Trigeminal schwannoma

Abstract

Schwannoma is a benign tumor of the nerve sheath arising from the perineural schwann cells. The nerves most commonly involved in schwannomas of the head and neck are the vagus and the cervical sympathetic chain. Trigeminal schwannomas are rare tumours. A 17 year old male patient with a chief complaint of swelling on face was diagnosed as suffering from bening tumor extending from cranial base (from foramen ovale) to the parapharengeal space. Mandibular access osteotomy was done to expose the tumor. Surgical excision of the tumor was done along with the preservation of the nerve. Schwannomas can occur along the pathway of any somatic or sympathetic nerve. Superficial schwannomas require simple exposure and excision but the one which are deep and large, may require complex access osteotomies. Careful surgery is required to preserve the nerve function. Once completely excised, the prognosis is excellent.

Keywords: Access osteotomy; schwannoma; trigeminal nerve.

Figure 1

Preoperative photograph showing large swelling on left side of face causing facial asymmetry

Figure 2

Intraoral photograph showing displaced soft palate

Figure 3

T2-weighted (a) axial, (b) coronal, and (c) sagittal images showing a large well-defined hyperintense oval mass extending from the region below left cavernous sinus, passing through foramen ovale (which is widened) and extending below in the left parapharyngeal space between medial and lateral pterygoid muscles

Figure 4

Excised tumor

Figure 5

1-year follow-up photograph showing reduced facial asymmetry

Figure 6

Intraoral photograph un-displaced soft palate

Figure 7

(a) Coronal T1-weighted image shows a mass to be hyperintense to muscle. (b) Coronal postcontrast T1-weighted image showing no enhancement, suggestive of fat