Surgical Approaches for Tongue Base Schwannoma:

Transoral Robotic Surgery in the Management of a Tongue Base Schwannoma

Schwannomas are the most common benign tumors arising from the peripheral nerve sheath, and the intraoral location is very atypical, representing less than 1% of all cases. Surgical excision is the treatment of choice, and a variety of surgical approaches have been described. The authors report the first described case of tongue base schwannoma treated with transoral robotic surgery (TORS). A 47-years-old female patient complaining mild dysphagia and snoring, presented a submucosal swelling at the right side of the tongue base. MRI showed a large well-circumscribed solid mass, homogeneously isointense in T1WI and hyperintense on T2WI, with no lymph node metastasis. According to size, location and radiological characteristic of the mass a TORS approach was chosen. An extracapsular dissection was performed, and the lesion was completely removed with no intraoperative complications. The final diagnosis based on histopathological examination and IHC analysis (S-100 positive) was a schwannoma of the tongue base. The post-operative course was uneventful, and no recurrence was observed after 6 months of follow-up. This study demonstrates the feasibility of TORS in the treatment of a tongue base schwannoma. This is a valid alternative to the common transoral approach in order to avoid more invasive external approaches, and further studies are recommended in order to clarify if this approach could be proposed as the first line treatment in selected cases.

Tongue Base Schwannoma

Intraoral schwannomas account for 1% of head and neck schwannoma, with tongue base schwannoma being reported rarely. In an English literature search from 1988 to 2014, not more than 38 cases of tongue base schwannoma have been reported. Large tongue base schwannomas pose a significant risk to airway, thereby calling for an early intervention. We report a rare case of tongue base schwannoma in a 25 year old female managed surgically by lateral pharyngotomy approach.

Clinical Features and Surgical Treatment of Schwannoma Affecting the Base of the Tongue: A Systematic Review

Introduction  Schwannomas of the head and neck account for 25–40% of all cases, with presentation at the base of the tongue as the most frequent site for intraoral tumors.

Objectives  Here, a systematic review was conducted to include 15 cases of patients with schwannoma of the base of the tongue.

Data Synthesis  Most patients presented with a single, painless, well-encapsulated nodule at the base of the tongue. These nodules were slow-growing, with an average of 13.3 months from onset to presentation. Most cases were accompanied by airway obstruction, indicated by symptoms of dysphagia, dysarthria, snoring, and sleep apnea. Overall, the histological studies were consistent with a benign schwannoma with a palisading Antoni A and Antoni B pattern without malignant changes in cell morphology. These tumors were treated via complete surgical excision, and all cases achieved full remission by final follow-up.

Conclusion  Surgical removal is the primary mode of treatment with excellent postoperative prognosis and rare instances of recurrence. Given the rarity of this tumor, this review of available case studies serves to comprehensively describe clinical presentation and surgical treatment approaches to tongue base schwannoma.

Schwannoma derived from lingual nerve occurring in floor of mouth

A schwannoma is a benign tumor composed of schwann cells which forms on the periphery of nerves. We report a case of a schwannoma derived from a lingual nerve occurring in the floor of the mouth. The patient was a 27-year-old woman who presented with the complaint of a swelling in the floor of the mouth. It is difficult to distinguish a swelling from a sublingual gland tumor, cyst, or malignant tumor by MRI alone. Therefore, a biopsy and cytological examination were performed one week prior to surgery to determine whether the growth represented a malignancy. The results revealed a class II growth which was suspected to be a schwannoma. Intraoperatively, it became clear that the tumor and lingual nerve were inseparable, making excision of the nerve unavoidable. On the other hand, there was a clear border between the tumor and the sublingual gland, so it was possible to preserve the sublingual gland. In the postoperative pathological diagnosis, a definitive diagnosis was difficult based solely on H-E staining. Therefore, immunohistochemical staining was performed, resulting in a diagnosis of schwannoma. Currently, the patient is still being followed up. The results of this case indicate that preoperative aspiration biopsy cytology is useful in deciding the operative method to be employed.