Unmasking Hypoglossal Nerve Schwannomas Mimicking Submandibular Salivary Gland Tumors: Case Report of a Rare Presentation and Surgical Management

Abstract

Background: Schwannomas are solitary neurogenic tumors originating from the myelin-producing cells of the neural sheath. Hypoglossal nerve schwannomas are exceedingly rare, particularly those extracranially originating and mimicking a submandibular salivary gland tumor. Methods: We report the case of a 31-year-old female who presented to our ENT department with a painless swelling in her left submandibular region that has persisted for approximately five months. Discussion: Due to the rarity of these tumors and their unique nature, a comprehensive diagnostic workup is imperative for accurate diagnosis. Surgical excision remains the gold standard treatment. Conclusions: Extracranial hypoglossal nerve schwannomas represent a rare clinical entity requiring a thorough diagnostic process for precise identification. The preferred treatment strategy for managing hypoglossal gland schwannomas involves complete tumor excision while preserving the facial nerve.

Extracranial Hypoglossal Schwannoma: Case Report and Literature Review

“…Hypoglossal schwannomas are typically found in middleaged patients, with a slight female predominance (12). They are usually solitary, encapsulated tumors that grow slowly and appear attached or surrounded by a nerve (13).…”

“…They are usually solitary, encapsulated tumors that grow slowly and appear attached or surrounded by a nerve (13). Imaging characteristics of hypoglossal schwannomas are often similar to those of submandibular salivary gland tumors or paragangliomas (2,12). Submandibular tumors are typically asymptomatic masses.…”

“…This provides information about the tumor's nature, size, and anatomical relationships with adjacent soft tissue structures and nerve courses (1, 7-9, 12, 16). However, accurate preoperative diagnosis can be impeded by the rarity of these entities, leading to a lack of specific radiological features (12). Therefore, the definitive diagnosis depends on the histopathological examination of the surgical specimen (12).…”

“…However, accurate preoperative diagnosis can be impeded by the rarity of these entities, leading to a lack of specific radiological features (12). Therefore, the definitive diagnosis depends on the histopathological examination of the surgical specimen (12). Here, two types of schwannomas cells are demonstrated.…”

“…Based on international consensus recommendations, surgical resection is the first-line treatment modality for extracranial hypoglossal schwannomas (1,1,3,4,7,9). Nerve-preserving surgery can be very challenging for head and neck surgeons and may not always be possible due to the difficulty in accurately diagnosing the condition before surgery and the complexity of the surgical site (2,12). In cases of nerve transection, direct nerve reconstruction can be considered to minimize potential functional neural morbidity postoperatively (2,3).…”