Schwannoma of the epiglottis: first report of a case. (Original Article).

Abstract

Schwannomas of the larynx are rare. Most of the few such reports in the literature have described schwannomas that occurred in the aryepiglottic fold or the true vocal folds. In this article, we report what we believe is the first case of a schwannoma arising from the epiglottis.

Introduction

Nerve sheath tumors were first described in 1910 by Verocay. (1) Neurogenic tumors include neuromas, neurofibromas, granular cell tumors, and schwannomas. Schwannomas are benign, encapsulated, submucosal, neural sheath tumors derived from Schwann's cells. (1-7) They are generally solitary and they can occur along any somatic or sympathetic nerve in the body except the olfactory and optic nerves, which lack Schwann's cell sheaths and which are part of the central nervous system.

When schwannomas do occur, approximately 25% arise in the head and neck region. (2) Head and neck schwannomas usually occur in either the aryepiglottic folds or the true vocal folds. Schwannomas account for less than 0.1% of all laryngeal neoplasms. (3) Most patients who have a laryngeal schwannoma exhibit symptoms of hoarseness, dysphagia, dyspnea, dysarthria, a globus sensation, and/or shortness of breath. (1-7)

In this article, we describe the case of a patient who had a large schwannoma of the epiglottis that was discovered during intubation for an unrelated procedure. To our knowledge, this is the first report in the literature of a schwannoma that involved the epiglottis.

Case report

The otolaryngology service was consulted to evaluate a 79-year-old man who had an epiglottic "cyst" that had been discovered incidentally during intubation for an orthopedic procedure. The patient was evaluated in the otolaryngology clinic, and a complete history and physical examination were performed. The patient was unaware of the mass and almost completely asymptomatic, although he did notice a minor globus sensation, chronic throat clearing, and cough that had been present for several years. On flexible fiberoptic examination, a smooth, pedunculated, 2.5-cm mass was seen on the superior lingual margin of the epiglottis (figure). The mass moved back and forth between the vallecula and the laryngeal vestibule; this motion caused an intermittent near-complete airway occlusion. The patient underwent direct laryngoscopy in the operating room and an excisional biopsy of the lesion was taken. Intraoperatively, the mass was found to be smooth and 2.5 cm in diameter. It originated in the superior lingual edge of the epiglottis, and it was sharply excised at its base. The remainder of the larynx was without abnormality and the patient's postoperative course was uneventful.

Microscopic analysis showed that the tumor was encapsulated and that it exhibited Antoni A (cellular) and Antoni B (myxoid) patterns with some areas of degenerative changes. The mass was strongly reactive for S-100 protein on immunoperoxidase studies.

At the 6-month follow-up, the patient had no evidence of recurrence. His globus sensation, chronic throat clearing, and cough had disappeared immediately after surgery.

Discussion

The natural history of schwannomas involves a slow increase in size until symptoms are produced by pressure on adjacent structures. Schwannomas located in the pharynx or larynx can cause symptoms of hoarseness, dysphagia, dyspnea, dysarthria, a globus sensation, and/or shortness of breath. (1-7) There is one reported case of death by asphyxiation from a laryngeal schwannoma. (4) Laryngeal schwannomas are nearly always solitary, submucosal, and circumscribed, and on occasion they can be painful. (1)

Some schwannomas have been associated with von Recklinghausen's disease; in these cases, cutaneous and visceral nodules and cafe au lait spots were also observed. (3) However, most cases reported in the literature were sporadic and not related to neurofibromatosis.

Histologically, schwannomas are encapsulated lesions that are characterized by cellular (Antoni A) and edematous (Antoni B) regions in varying proportions. (4) Cellular areas that display palisading of nuclei and pooling of cytoplasm (Verocay' s bodies) are pathognomonic for schwannoma. The Antoni B pattern is less cellular, lacks palisades, and is more prone to degeneration, cyst formation, and the superimposition of inflammatory changes. (4) Immunohistochemically, schwannomas demonstrate S-100 positivity.

Surgery is the treatment of choice for schwannomas of the head and neck because these tumors are usually benign, radioresistant, and do not recur on long-term follow-up.

References

(1.) al-Otiesehan AT, Mahasin ZZ, Gangopadhyay K, et al. Schwannoma of the larynx: Two case reports and review of the literature. J Otolaryngol 1996;25:412-5.

(2.) Triaridis C, Tsalighopoulos MG, Kouloulas A, Vartholomeos A. Posterior pharyngeal wall schwannoma (case report). J Laryngol Otol 1987; 101:749-52.

(3.) Cadoni G, Bucci G, Corina L, et al, Schwannoma of the larynx presenting with difficult swallowing. Otolaryngol Head Neck Surg 2000; 122:773-4.

(4.) Gardner PM, Jentzen JM, Komorowski RA, Harb JM. Asphyxial death caused by a laryngeal schwannoma: A case report. J Laryngol Otol 1997;l1l:117l-3.

(5.) Haraguchi H, Ohgaki T, Hentona H, Komatsuzaki A. Schwannoma of the posterior pharyngeal wall: A case report. J Laryngol Otol 1996; 110:170-1.

(6.) Sanghvi V. Lala M, Borges A, et al. Lateral thyrotomy for neurilemmoma of the larynx. J Laryngol Otol 1999;l13:346-8.

(7.) Moore CE, Putzi M, MeClatchey KD, Terrell J. Ancient schwannoma of the posterolateral pharynx: A benign lesion commonly mistaken for sarcoma. Otolaryngol Head Neck Surg 1997; 117:S125-8.

From the Department of Otolaryngology-Head and Neck Surgery, Loma Linda (Calif.) University.

Reprint requests: Paul A. Martin, MD, Department of Otolaryngology--Head and Neck Surgery, Loma Linda University, 11234 Anderson St., Loma Linda, CA 92354. Phone: [phone]; fax: [phone]; e-mail: [e-mail]