Isolated Hypoglossal Nerve Schwannoma: An Uncommon Presentation of Schwannoma

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

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.

Mandibular Canal Enlargement: Clinical and Radiological Characteristics

Enlargement of the mandibular canal is a rare radiological finding. Clinically, it may or may not be associated with sensory deficits. We report four cases of widening of the mandibular canal observed with various methods of imaging with different clinical characteristics. We describe this unique radiological finding and elaborate the importance of quality assessment of the imaging that is vital for accurate diagnosis and treatment planning. Clinicians should be mindful when assessing the imaging whenever the size of the mandibular canal is implicated. The case ranged from a benign tumor to malignancy, radiological errors, and artifacts. A more superior imaging or treatment modality was necessary to ascertain the diagnosis.

Schwannoma of the hypoglossal nerve: Review of the literature based on an illustrative case

Schwannomas are benign tumours that originate from the myelin sheath of peripheral nerves. They are characterised by a slow growth tendency. Benign schwannomas represent 35% of the head and neck district tumours. Hypoglossal schwannomas account for 5% of non-vestibular schwannomas, and malignant schwannomas occur very rarely. In the present case report, the case of a 49-year-old man who presented with paraesthesias in the left parotid and submandibular region, associated with sensation of foreign bodies and dysphagia for solids, is described. A clinical examination revealed the presence of an ovoid palpable mass in the lateral-cervical region of the neck. The patient subsequently underwent excisional surgery, and neuropathological evaluation of the specimen confirmed the diagnosis of benign schwannoma with Antoni areas A and B. Despite the rarity of schwannomas, this condition should be considered in differential diagnoses for masses localised in the neck, as in cases where they reach considerable sizes (>3 cm in diameter). Surgery therefore represents the first-choice treatment.

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

INTRODUCTION

Schwannomas of the descending loop of the hypoglossal nerve are very rare. They are slow-growing tumors that may masquerade a carotid body tumor.

PRESENTATION OF CASE

A 60-year-old female was referred for a latero-cervical mass appearing as a chemodectoma at CT-scan. At operation, a 2cm mass arising from the descending loop of the hypoglossal nerve was resected en bloc with the loop itself and a functional lymphadenectomy was associated. Post-operative course was uneventful and the patient is free from disease recurrence at one year follow-up.

DISCUSSION

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, beside requiring reintervention, it may harbor a malignant evolution towards sarcoma.

CONCLUSION

Schwannomas of the descending lop of the hypoglossal nerve may masquerade a chemodectoma of the carotid bifurcation and can be curatively resected without any functional impairment.