Schwannoma of the descending loop of the hypoglossal nerve: case report

Abstract

Schwannomas of the descending loop of the hypoglossal nerve are very rare. Existing literature of the schwannoma of the descending loop of the hypoglossal nerve is limited to two previously reported case. They are slow-growing tumors that may masquerade a carotid body tumor. We herein described a rare case of schwannoma of the descending loop of the hypoglossal nerve in the s right latero-cervical region with diagnostic imaging and histopathological findings. A 37-years-old woman has had a palpable firm, mobile mass in the right latero-cervical region, of imaging, MR images showed homogeneous hypointensity on T1-weighted imaging (T1-WI), heterogeneous hyperintensity on T2-WI, and heterogeneous enhancement on contrast-enhanced T1-WI. Diagnostic imaging using computed tomography (CT) and magnetic resonance imaging (MRI) was suspected of Chemodectoma or neurogenic tumor. At operation, a 4 cm mass arising from the descending loop of the hypoglossal nerve of was resected en bloc with the loop itself; Final diagnosis was confirmed on the basis of histopathological finding and intraoperative findings. Postoperative course was uneventful and the patient is free from disease recurrence at tree-year follow-up. En bloc resection remains the real curative treatment of Schwannomas, ensuring unlimited freedom from disease, although causing functional impairment which may be significant. Nonetheless recurrence should be prevented as, besides requiring reintervention, it may harbor a malignant evolution towards sarcoma. Schwannomas of the descending loop of the hypoglossal nerve may masquerade a chemodectoma of the carotid bifurcation and can be curatively resected without any functional impairment. This case confirmed the differential diagnosis on the basis of the intraoperative finding that the tumor was continuous with the hypoglossal nerve.

Quantification of vessel separation using the carotid-jugular angle to predict the nerve origin of neck peripheral nerve sheath tumours: a pooled analysis of cases from the literature and a single-center cohort

“…Additionally, one, two, and five patients with PNSTs originating from the glossopharyngeal, spinal accessory, and hypoglossal nerve was reported in the literature, respectively (Supplementary Table 2, Supplemental Digital Content 2, http://links.lww.com/JS9/A521 ) 17 , 67 – 73 .…”

Pediatric schwannoma of the hypoglossal nerve: a case report and narrative literature overview

“…They usually develop from the sensory cranial nerves, most commonly the eighth and tenth nerves (the acoustic and vagus). Schwannomas of the hypoglossal nerve (12th cranial nerve) are rare, as this is a purely motor nerve ( 1 , 4 , 6 , 7 ). However, schwannomas arising from this nerve are usually associated with hemiatry, fasciculations, and tongue deviation during protrusion, which can (rarely) also be caused by schwannomas of the cervical vagus nerve.…”

“…Schwannomas tend to occur in the parotid gland, nose, paranasal sinuses, and oral cavity, but they occur rarely in other locations. Schwannomas originating from the descending loop of the hypoglossal nerve are particularly rare ( 1 , 2 ). Since De Martel and colleagues first described a hypoglossal schwannoma in 1933, only a few case reports of extracranial schwannomas have been described.…”

An unexpected complication of hypoglossal schwannoma surgery: Cerebrospinal fluid leakage—A case report and literature review

“…Hypoglossal schwannoma is a rare tumor among extracranial head and neck schwannomas, particularly when it originates from the descending loop of the hypoglossal nerve 5,7,8 . The current literature recommends surgical excision as the first‐line treatment for schwannoma.…”

“…Hypoglossal schwannoma is a rare tumor among extracranial head and neck schwannomas, particularly when it originates from the descending loop of the hypoglossal nerve. 5,7,8 The current literature recommends surgical excision as the first-line treatment for schwannoma. For Schwannomas arising from other cranial nerves, excision of the mass en bloc with the entire nerve is the best option in order to achieve a curative treatment.…”