Hypoglossal Schwannoma of Neck: Case Report and Review of Literature.

BACKGROUND

Schwannomas are benign, slow-growing neoplasms of the myelin-producing Schwann cells of peripheral nervous system that most commonly affect sensory nerves. Hypoglossal schwannomas, tumors of purely motor nerves, comprise <5% of all head and neck schwannomas. Since the first description of a hypoglossal schwannoma in 1933, there have been few case reports of extracranial origins. The most common location of an extracranial hypoglossal schwannoma is in the parapharyngeal space and can mimic paragangliomas. We describe the case of a woman presenting with an enlarging neck mass originally thought to be a paraganglioma but ultimately discovered to be a hypoglossal schwannoma at surgery.

CASE DESCRIPTION

A 63-year-old woman had a well-circumscribed, mobile, nontender, 3-cm firm mass at the mandibular angle. On computed tomography, the mass was at the level of the carotid bifurcation, splaying the branching vessels. It was further evaluated with magnetic resonance imaging, which revealed a homogeneous, T2-hyperintense, T1-isointense mass with homogeneous contrast enhancement and scant flow voids. Biopsy revealed a spindle cell mass with positive S-100 staining. She underwent resection with the mass originating from the hypoglossal nerve.

CONCLUSIONS

Hypoglossal schwannomas are rare lesions with a variable location along the course of the nerve. An extracranial lesion was described here, which was initially mistaken for a paraganglioma. Surgical resection is the consensus recommendation and is often well tolerated with low risk of long-term recurrence.