A large extra cranial cystic trigeminal schwannoma of the parapharyngeal space - exploring the right approach

Combined open maxillectomy and endoscopic endonasal resection of a giant V2 trigeminal schwannoma

BACKGROUND

Trigeminal schwannoma is a rare type of tumor that arises from the Schwann cells of the trigeminal nerve.

METHOD

We present a case of a patient with a giant V2 trigeminal schwannoma with painful swelling in the left maxilla. A complete resection using a combined open maxillectomy and endoscopic endonasal approach was performed.

CONCLUSION

This case highlights the importance of a multidisciplinary approach to perform a combined open and endoscopic approach for safe resection while preserving adequate speech and swallowing.

Comprehensive Analyses of Intraoral Benign and Malignant Nerve Sheath Tumors: The Rare Disease Entities Revisited

INTRODUCTION

Intraoral benign and malignant nerve sheath tumors (BNST and MNST) are rare tumors with non-specific clinical presentations and represent diagnostic and therapeutic challenges. Current knowledge regarding their demographic, clinicopathological features and treatments remains fragmented.

MATERIALS AND METHODS

The original data about patients diagnosed as intraoral BNST and MNST were retrieved from our disease registry (2005-2017). Comprehensive reviews of English and Chinese literature were performed to collect and analyze the epidemiological, clinicopathological data and treatment outcomes about those published cases.

RESULTS

Thirty-four intraoral BNSTs were found at our institution in the past 13 years. Literature reviews identified 354 intraoral BNSTs in 223 articles and 60 intraoral MNSTs in 50 articles. Most intraoral BNSTs and MNSTs were presented in the second to fifth decade of life. Males outnumbered females in MNSTs, while BNSTs displayed a slight female preponderance. The common sites for intraoral BNSTs were parapharyngeal space followed by tongue, whereas mandible was the most common site for MNSTs. Most intraoral BNSTs were presented as slow-growing, painless mass or swelling, while MNSTs usually appeared as painful and invasive mass with discomfort. Surgical excision was preferred for intraoral BNSTs with excellent prognosis. Complete resection was indicated for intraoral MNST with dismal prognosis as evidenced by much recurrence, metastasis, and death.

CONCLUSION

Intraoral BNST and MNST are rare diseases which should not be ignored when intraoral painless or painful mass/swelling is found. Surgical excision is indicated for intraoral BNST with favorable outcomes. However, further investigations are warranted to optimize the treatment for intraoral MNST to improve its prognosis.

Endoscopic Transvestibular Transmandibular Approach for Trigeminal Schwannoma in Infratemporal Fossa and Parapharyngeal Space

BACKGROUND

Schwannomas that involve the mandibular division of the trigeminal nerve and localize exclusively in the parapharyngeal space (PPS) and infratemporal fossa (ITF) are extremely rare, and a surgical approach to treat such tumors has not been well established.

CASE DESCRIPTION

We present our experience in the treatment of a giant trigeminal schwannoma with wide extension in the ITF and PPS using an endoscopic transvestibular transmandibular approach. The clinical and radiologic findings, preoperative planning, advantages of the surgical approach, and clinical outcome are discussed.

CONCLUSIONS

Schwannomas located in the ITF and PPS are rare benign neoplasms. They are usually detected late after considerable signs and symptoms appear. Preoperative planning is beneficial to individual surgical approach selection. Total surgical excision following careful evaluation of preoperative computed tomography and magnetic resonance images is the treatment of choice. Recurrence is rare after complete excision.

Head and Neck Schwannomas: A Surgical Challenge-A Series of 5 Cases

Background

Schwannomas, also known as neurilemmomas, are benign peripheral nerve sheath tumors. They originate from any nerve covered with schwann cell sheath. Schwannomas constitute 25–45% of tumors of the head and neck. About 4% of head and neck schwannomas present as a sinonasal schwannoma. Brachial plexus schwannoma constitute only about 5% of schwannomas. Cervical vagal schwannomas constitute about 2–5% of neurogenic tumors.

Methods

We present a case series of 5 patients of schwannomas, one arising from the maxillary branch of trigeminal nerve in the maxillary sinus, second arising from the brachial plexus, third arising from the cervical vagus, and two arising from cervical spinal nerves.

Result

Complete extracapsular excision of the tumors was achieved by microneurosurgical technique with preservation of nerve of origin in all except one.

Conclusion

Head and neck schwannoma though rare should be considered as a differential diagnosis of a unilateral slow growing mass in the head and neck region, particularly in an adult. Schwannomas are always a diagnostic dilemma as they are asymptomatic for long time, and histopathology is the gold standard for diagnosis. As a rule, treatment is surgical and dictated by the location of the tumor and nerve of origin. Due to its rarity, complex anatomical location and morbidity risk postexcision, they can pose a formidable challenge to surgeons. This study aims to describe the presentation, workup, surgical technique, and outcome.

Parapharyngeal Schwannoma of the Mandibular Nerve Associated With Auditory Changes

We present a case of a parapharyngeal schwannoma of the mandibular nerve with intraosseous extension into the mandible. The initial symptoms included decreased auditory acuity, with subsequent magnetic resonance imaging findings suggestive of Eustachian tube obstruction. This represents a rare symptom of schwannomas of the mandibular nerve. Owing to the degree of bony expansion and cortical thinning of the adjacent mandibular ramus, concern existed for a pathologic fracture. Treatment involved complete excision of the lesion using hemimandibulectomy with second stage reconstruction. The patient noted resolution of the preoperative symptoms. No sign of recurrence of the schwannoma was noted at the 2-year mark.

Diagnostic dilemma involving a mass in the parapharyngeal space: A metastatic breast carcinoma masquerading as a malignant salivary gland tumor

Parapharyngeal space (PPS) tumors are rare and account for about 0.5% of all head and neck neoplasms. Most PPS tumors are benign (up to 80%) while the remaining 20% are malignant. These tumors are either primaries; most commonly arising from salivary glands or metastatic tumors or due to direct extension of tumors from the adjacent sites. Distant metastasis from breast cancers more commonly involves the lungs, bones, brain and liver. Metastasis to the PPS from a primary breast carcinoma is rare, with only one case reported in literature. We, to the best of our knowledge report the second case of a carcinoma breast metastasizing to the PPS and further discuss the diagnostic and therapeutic challenges involved in its management. A fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography scan apart from explicitly defining the extent of the PPS tumor, majorly influenced the therapeutic decision making process by ruling out other sites of metastasis.