|Year : 2020 | Volume
| Issue : 1 | Page : 24-27
Obstructive laryngeal schwannoma - A rare tumor excised transorally
Vaibhav Saini1, Shashikant A Pol2, Sanjeev Yadav1, Anand Subhash3
1 Lady Hardinge Medical College, New Delhi, India
2 Government Medical College and Hospital, Chandigarh, India
3 HCG Bangalore, Bengaluru, Karnataka, India
|Date of Submission||11-Aug-2019|
|Date of Decision||27-Oct-2019|
|Date of Acceptance||19-Nov-2019|
|Date of Web Publication||01-Jun-2020|
Dr. Sanjeev Yadav
Room 207-RMO-B, Lady Hardinge Medical College, New Delhi - 110 001
Source of Support: None, Conflict of Interest: None
Laryngeal schwannomas are rare benign encapsulated nerve sheath tumor, which are difficult to manage and a patient may require tracheostomy before definitive management. The present case report is of a 35-year-old female complaining of change in voice quality, snoring with infrequent apnea episodes, dyspnea more on exertion, and lying supine. The patient underwent complete excision using microdebrider-assisted transoral microlaryngoscopy, thus avoiding the need of imminent tracheostomy. Postoperative after 2 months, the patient had normal voice and vocal fold mobility with preserved laryngeal mucosa. Although a novel technique, it is quite effective and safe in the excision of laryngeal Schwannoma without injury to the surrounding structures.
Keywords: Laryngeal schwannoma, microdebrider, tracheostomy
|How to cite this article:|
Saini V, Pol SA, Yadav S, Subhash A. Obstructive laryngeal schwannoma - A rare tumor excised transorally. Saudi J Otorhinolaryngol Head Neck Surg 2020;22:24-7
|How to cite this URL:|
Saini V, Pol SA, Yadav S, Subhash A. Obstructive laryngeal schwannoma - A rare tumor excised transorally. Saudi J Otorhinolaryngol Head Neck Surg [serial online] 2020 [cited 2020 Jul 16];22:24-7. Available from: http://www.sjohns.org/text.asp?2020/22/1/24/285556
| Introduction|| |
Schwannoma is a benign neurogenic tumor arising from Schwann cells of peripheral nerve sheath. About 50% of all neurogenic tumors arise in the head-and-neck region, most commonly in parapharyngeal space. Laryngeal schwannoma is quite uncommon, accounting 0.1%–1.5% of all benign laryngeal neoplasm. Most common nerve of the origin remains internal branch of the superior laryngeal nerve once it pierces thyrohyoid membrane. Most common location of these tumors is supraglottis, sites being aryepiglottic fold (80%) and false cords (20%). Swchank described the first case in the literature in 1925. Commonly found in middle-aged females in their fourth and fifth decades. Only very few of reported cases have been managed by the transoral microlaryngoscopic (TOML) approach without tracheostomy.
Here, we present a case of 35-year-old female having Schwannoma arising from the right aryepiglottic fold completely excised by the microdebrider-assisted TOML approach in a single sitting using intraoperative frozen section for presumptive diagnosis obviating need for imminent tracheostomy. Informed written consent has been taken from patient. To the best of our knowledge, microdebrider has never been used for the excision of laryngeal Schwannoma.
| Case Report|| |
A 35-year-old female presented to the otolaryngology outpatient clinic with complaints of change in voice quality, foreign body sensation in throat, difficulty in breathing on exertion or lying supine, and snoring at night with infrequent apnea episodes. The patient had no known systemic illness and is nonsmoker and nonalcoholic.
Laryngoscopy revealed a mucosal-covered bulge with prominent vascularization in the supraglottic region over the right aryepiglottic fold and right false vocal cord, and also involving right pyriform sinus [Figure 1]. Right true vocal fold was not visible, so its mobility could not be assessed. The left vocal fold was mobile with minimally compromised airway. Computed tomography (CT) showed well-defined hypodense supraglottic lesion arising from the right aryepiglottic fold obstructing the supraglottic airway [Figure 2]. The patient was prepared for transoral suspension microlaryngoscopy. Intraoperative frozen section of the mass revealed Schwannoma. Considering the size of tumor and patient's profile, tumor was excised transorally with assistance of microdebrider. Intraoperative hemostasis was achieved with neuropatty soaked in 1:5000 adrenaline solution. Nerve of the origin could not be identified. Postoperative recovery was uneventful, and the patient was discharged on the same day. Follow-up laryngoscopy performed after 2 weeks revealed no residual lesion with bilateral true vocal folds freely mobile. Patient's voice recovered to near normal with no dyspnea and snoring.
|Figure 1: Direct laryngoscopy showing supraglottic mass obstructing laryngeal inlet|
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|Figure 2: Computed tomography: coronal section in neck depicting well-defined hypodense supraglottic lesion arising from the right aryepiglottic fold obstructing the supraglottic airway|
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Gross tumor specimen was measuring 4 cm × 2 cm × 0.6 cm, gray white in color [Figure 3]. Microscopic examination showed tumor composed of alternate predominantly hypercellular Antoni A and occasional hypocellular areas [Figure 4]. Verocay body formation was also noted [Figure 5] and [Figure 6]. Overall, features were suggestive of Schwannoma.
|Figure 3: Gross tumor specimen measuring 4 cm × 2 cm × 0.6 cm, gray white in color|
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|Figure 4: Schwannoma with well-formed capsule and alternating Antoni A and B areas; H and E, ×100|
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|Figure 5: Antoni A areas illustrating nuclear palisading with Verocay bodies and Antoni B areas are less cellular; H and E, ×200|
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|Figure 6: S-100 immunostain shows nuclear as well as cytoplasmic positivity in tumor cells, particularly in the Antoni A areas; ×400|
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| Discussion and Conclusions|| |
Schwannoma is a benign encapsulated slow-growing neurogenic tumor arising from the Schwann cells of the peripheral nerve sheath, first described by Verocay. Laryngeal schwannoma is quite rare, only few sporadic cases are reported in the English literature.
Laryngeal Schwannoma usually assumed to originate from medial ramification of the internal branch of the superior laryngeal nerve. This finding is not often appreciable intraoperatively, as tumor is likely to arise from distal nerve fibers to laryngeal submucosa. They are commonly located at aryepiglottic fold followed by ventricular folds and may extend to pyriform sinus. Involvement of vocal folds and subglottis is rare. Risk of malignant transformation is very rare in these cases.
The clinical features are usually having slowly progressive long-standing history mainly attributable to a mass lesion in the supraglottic region. Patients mainly had complaints of hoarseness, globus sensation, odynophagia, snoring, and even sleep apnea. Corresponding to size of tumor, the patient may have complaints of dyspnea more on exertion and on supine position, as in our case, requiring prompt intervention. At least one asphyxial death has been reported due to laryngeal schwannoma. Hoarseness is due to mass effect decreasing laryngeal mobility. This may mimic cricoarytenoid joint fixation (pseudofixation), and rarely tumor may be originating from true vocal cords.
Diagnostic workup includes laryngoscopy, imaging, and biopsy. Most common finding on laryngoscopy is smooth submucosal bulge usually in aryepiglottic fold or false cord. Both CT and magnetic resonance imaging (MRI) can be used for diagnosis. Typical CT findings appear as ovoid, submucosal, well-defined, nonenhancing mass, mostly in the supraglottic region without signs of invasion. On MRI, schwannoma appears as hyperintense center with peripheral hypointensity on T1-weighted images, hyperintense in T2-weighted sequences, and on gadolinium contrast.
Differential diagnoses include neurofibroma, laryngeal cyst, internal laryngocele, and other benign laryngeal neoplasms as chordoma and adenoma. Clinically, it is imperative to differentiate between schwannoma and neurofibroma. As neurofibroma is associated with high chances of recurrences, high malignant potential, and neurofibromatosis should be excluded from the study.
Gold standard for the diagnosis is histological examination. Enzinger and Weiss described three criteria for diagnosing schwannoma: encapsulation, presence of Antoni A and Antoni B areas, and S-100 positivity on immunohistochemistry.
Complete surgical excision is the mainstay of treatment. Keys to better surgical outcome are associated with preservation of laryngeal function and laryngeal mucosa during surgery. As schwannoma is a benign, slow-growing tumor, tracheostomy should also be avoided to maintain the quality of life. Surgical approach depends on size, location, as well as extent of lesion. Moderate to smaller lesion should be managed by the transoral microlaryngeal approach. In cases of extensive and recurrent tumor, external approach may be required with or without preoperative tracheostomy. Various approaches mentioned are medial thyrotomy, lateral thyrotomy, and laryngofissure. Laser-assisted transoral excision has also been advocated along with its own benefits. Kayhan et al. demonstrated robot-assisted transoral excision. Although never been used but powered instrument (microdebrider) can also be used to assist surgeon in completely removing tumor.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]