Laryngeal schwannoma: case report and literature review

Transoral Endoscopic-Assisted Resection of Laryngeal Schwannoma: A Case Report

Introduction

Schwannoma, a peculiar benign nerve sheath tumour, is frequently hard to differentiate from other nerve tumours, such as neurofibroma. Around 25%-45% of all schwannomas emerge in the head and neck region, but only 0.1-1.5 % involve laryngeal structure. This tumour is most accurately diagnosed with biopsy via direct laryngoscopy; however, at some points this approach cannot detect a definitive diagnosis due to the surrounding capsule of the tumour and its similar histopathologic finding with other nerve sheath tumour.

Case Report

Here, a case of 56-year-old female is reported with chief complaints of severe progressive dyspnea and dysphagia. Diagnosis of schwannoma was confirmed on radiological and histopathological examination with certain hurdles. A complete surgical excision via endoscopic approach was done, revealing that the bottom of the mass was attached to the right arytenoid mucosa. The histopathological features showed non-malignant atypical neurofibroma but later confirmed as laryngeal schwannoma from immunohistochemical staining.

Conclusion

Although schwannoma has an excellent outcome and prognosis when occurring elsewhere in the body, laryngeal involvement is an extremely rare area for this lesion. Complete resection with a patient-customized approach to the lesion is required to avoid relapses and provide good functional results.

Schwannoma of the Supraglottis

Hoarseness lasting greater than 2 weeks should be thoroughly evaluated. Here, a case is presented of a 38-year-old female with a 10-year history of dysphonia. Endoscopic examination confirmed the presence of a supraglottic mass, for which operative biopsy and imaging were performed. Pathology confirmed the diagnosis of supraglottic schwannoma. This was excised endoscopically with close management postoperatively to monitor for rapid recurrence and airway compromise. At one month postoperatively, the patient is still mildly dysphonic but vocally improved and the operative site continues to heal well.

Solitary neurofibroma of the larynx: a diagnostic challenge

Solitary neurofibromas of the larynx are extremely rare, with a total of 15 cases described in the literature. Nonetheless, acquaintance with this diagnosis is important, as misdiagnoses can have negative consequences. Presenting symptoms are non-specific and depend on tumour size and location. As well-defined submucosal masses with a broad differential diagnosis, they remain a clinical and radiological challenge. While some characteristics might favour a benign nature and subtle signs might help narrow the differential diagnosis, imaging alone is not sufficient for differentiation and definitive diagnosis requires a biopsy. Complete surgical resection and long-term follow-up is indicated. We share our experience on a case of a solitary laryngeal neurofibroma in a middle-aged woman, presenting with a large well-defined paraglottic lesion.

Diagnosis and Treatment of Laryngeal Schwannoma: A Systematic Review

Objective

This review summarizes the clinical features, diagnostic workup, and surgical treatment of laryngeal schwannoma with the aim of providing guidance for the management of this rare disease. The collated data allowed the statistical testing of several hypotheses, including the efficacy of endoscopic vs open surgical intervention and the usefulness of preoperative biopsy.

Data Sources

PubMed, Google Scholar, Cochrane, and SCOPUS.

Review Methods

Basic epidemiological and clinical presentation data were collated together with details of diagnostic image modality, lesion attributes, and the use of preoperative biopsy. Surgical approach to intervention and outcome was also collated and simple statistical analyses applied.

Results

The 60 original articles selected provided a combined cohort of 74 patients for review. The combined data revealed that schwannoma with pedunculated morphology were always safely removed by endoscopic resection regardless of size and should be treated as a separate entity. Of the nonpedunculated schwannoma, larger tumors were more likely to undergo an open approach, which in turn was associated with higher rates of tracheotomy and postoperative vocal fold paralysis. The small cohort did not reveal a significant association between surgery type and persistent disease. Interestingly, the data revealed a significant association between the use of incisional biopsy and persistent disease. Cases exhibiting extralaryngeal extension of the lesion were shown to exclusively belong to patients with neurofibromatosis/schwannomatosis syndromes.

Conclusions

Taken together, these findings suggest that incisional biopsy should be avoided, and given the benign nature of the pathology, the least invasive radical approach should be employed.

Laryngeal schwannoma: a systematic review

A large proportion of schwannomas are found in the head and neck region. Schwannoma located within the larynx however is uncommon. The characteristic features, clinical presentations, treatment and the outcomes of patients with laryngeal schwannoma are therefore not clearly understood. The aim of this comprehensive review is to compile, analyze and present the details to develop a consensus and augment the available literature on laryngeal schwannoma. A comprehensive literature search on laryngeal schwannoma was performed on PUBMED/MEDLINE, EMBASE, CINAHL and Science Citation Index using MeSH words. A total of 55 patients were reviewed in this study. 40.7 % of the tumours arose from the aryepiglottic fold or arytenoids. Other areas where tumours were found included the false cord, true vocal cord, epiglottis, subglottis, piriform sinus and the post cricoid area. 64.9 % patients presented with dysphonia. Others typically present with multiple symptoms related to the mass effect and location of the tumour. All patients were managed surgically with different techniques and approaches. Majority of patients were alive with no residual disease. There were five recurrences and no mortality to date. Schwannoma within the larynx can present with a variety of symptoms. Surgical excision remained as the treatment of choice with good overall prognosis.

Trauma-induced schwannoma of the recurrent laryngeal nerve after thyroidectomy

Laryngeal schwannomas are rare, benign tumors, most often arising from the superior laryngeal nerve. We describe a case of a 68-year-old female with a laryngeal schwannoma of the recurrent laryngeal nerve after traumatic injury. We postulate that trauma to the recurrent laryngeal nerve during thyroidectomy or thyroplasty incited growth of a nerve sheath tumor. This is the first reported case of a trauma-induced schwannoma of the recurrent laryngeal nerve and second case of a recurrent laryngeal nerve schwannoma. Although rare, this case demonstrates that these tumors should be considered during workup of vocal cord paresis after surgery or failed thyroplasty. Laryngoscope, 126:1408-1410, 2016.