Laryngeal neurilemmoma: a case report.Abstract
Published reports of benign nerve sheath tumors of the larynx are extremely rare. Because these tumors represent a potential threat to the airway, prompt diagnosis and treatment are vital. We report a case of a neurilemmoma that arose from the right arytenoid muscle adjacent to the arytenoid cartilage arytenoid cartilage
Either of a pair of small pyramidal laryngeal cartilages that articulate with the lamina of the cricoid cartilage and give attachment to the posterior part of the corresponding vocal ligament and to several muscles. . The mass was completely excised, and no recurrence was observed during follow-up. We discuss the diagnosis and management of this rare tumor
Benign nerve sheath tumors of the larynx are extremely uncommon. When they do occur, they pose a potential threat to the airway, so accurate diagnosis and prompt treatment are vital. Very few reports of either laryngeal neurilemmomas (schwannomas) or neurofibromas are found in the literature. We report a case of a neurilemmoma that arose from the fight arytenoid muscle.
A 50-year-old woman was referred by her general practitioner for evaluation of a 3-month history of intermittent dysphagia. She had no history of sore throat or voice alteration, but she did experience occasional dyspepsia. She had stopped smoking 2 years earlier. She had no other significant history.
Findings on physical examination, including indirect laryngoscopy, were normal. Likewise, esophagoscopy and direct laryngoscopy revealed that the postcricoid space and esophagus were normal. However, we did make an incidental finding of a small swelling on the right arytenoid muscle adjacent to the arytenoid cartilage (figure 1). Although this finding did not explain the patient's symptoms, the lesion was excised, and histopathology revealed that it was a benign nerve sheath tumor. The excised light-yellow lesion measured 0.3 cm and was well circumscribed circumscribed /cir·cum·scribed/ (serk´um-skribd) bounded or limited; confined to a limited space.
Bounded by a line; limited or confined. . Microscopic evaluation identified Antoni A areas that were made up of a proliferation of spindle-shaped stromal cells arranged in compact sheets. Characteristic Antoni B areas were also present; they featured haphazardly arranged spindle cells in looser myxoid myxoid /myx·oid/ (mik´soid) mucoid.
Containing or resembling mucus; mucoid.
myxoid adjective 1. areas (figure 2). Immunohistochemically, the spindle cells showed diffuse positivity for S-100 protein, which helped confirm the diagnosis of a laryngeal neurilemmoma.
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Postoperatively, no evidence of a laryngeal neurologic deficit was observed. The patient's voice was preserved unaltered, and her swallowing of both solids and liquids returned to normal. Although it must be assumed that we excised part of the nerve of origin along with the lesion, this resulted in no detectable neurologic dysfunction.
At the 6-month follow-up, the patient's dysphagia and dyspepsia had resolved following a short course of a proton-pump inhibitor, and repeat examinations detected no recurrence of the laryngeal swelling.
Neurilemmomas are peripheral nerve sheath tumors derived from Schwann's cells. They are significantly more likely to affect sensory nerves than motor nerves. (1) These tumors are typically slow growing, solitary, well circumscribed, and located on the proximal nerves or spinal nerve roots Spinal nerve roots can refer to:
von Recklinghausen's disease Neurofibromatosis, type 2 Neurology An AD condition characterized by cafe-au-lait skin spotting and pendulous fibrous tumors. . Neurilemmomas affect both sexes equally, and they occur most often during the fifth and sixth decades of life. (2) Approximately 50% of all neurilemmomas are located in the head and neck region, with the most common site being the parapharyngeal space. (3,4) Neurilemmomas of the larynx are extremely rare. One study showed that only 1 of 722 benign tumors of the larynx was a neurilemmoma. (5)
Neurilemmomas typically affect nerve sheaths but not usually nerve fibers. Symptoms, therefore, are dependent on the site of origin. Most peripheral neurilemmomas present as palpable masses; they may be painful, but they are seldom associated with a neurologic deficit. Intracranial neurilemmomas, such as acoustic neuromas, may develop within the internal auditory meatus The internal acoustic meatus (also internal auditory meatus) is a canal in the temporal bone of the skull that carries nerves from inside the cranium towards the middle and inner ear compartments. and compress the VIIIth cranial nerve, leading to symptoms such as deafness and tinnitus.
Most neurogenic neurogenic /neu·ro·gen·ic/ (-jen´ik)
1. forming nervous tissue.
2. originating in the nervous system or from a lesion in the nervous system. tumors of the larynx originate in either the aryepiglottic fold or the false vocal folds. (4) In these locations, the nerve of origin is likely to be the recurrent laryngeal nerve recurrent laryngeal nerve
A branch of the vagus nerve that supplies the cardiac, tracheal and esophageal branches and terminates as the inferior laryngeal nerve. or the internal branch of the superior laryngeal nerve superior laryngeal nerve
A branch of the vagus nerve at the inferior ganglion. At the thyroid cartilage, it divides into two branches, the internal, which supplies the mucous membrane of the larynx above the vocal cords; and the external, which . As a laryngeal neurilemmoma expands, it projects into the laryngeal airway. This projection is unlikely to cause symptoms initially, but as the lesion increases in size, it may interfere with the vocal folds and give rise to dysphonia dysphonia /dys·pho·nia/ (-fo´ne-ah) a voice impairment or speech disorder.dysphon´ic
Difficulty in speaking, usually evidenced by hoarseness. . A much larger tumor will eventually compromise the airway and lead to stridor Stridor Definition
Stridor is a term used to describe noisy breathing in general, and to refer specifically to a high-pitched crowing sound associated with croup, respiratory infection, and airway obstruction. .
No characteristic features suggest a neurilemmoma on simple inspection with the naked eye. Although computed tomography and magnetic resonance imaging magnetic resonance imaging (MRI), noninvasive diagnostic technique that uses nuclear magnetic resonance to produce cross-sectional images of organs and other internal body structures. have been shown to help delineate between benignity be·nig·ni·ty
n. pl. be·nig·ni·ties
1. The quality or condition of being kind and gentle.
2. A kindly or gracious act. and malignancy in larger tumors, (6) the diagnosis is usually made by the pathologist. Both fine-needle aspiration and incisional biopsy have been used, but the literature indicates that excision of the tumor is the most reliable treatment. (6)
Pathologically, neurilemmomas are made up almost entirely of Schwann's cells. Three criteria are necessary to establish a histopathologic diagnosis: the presence of a capsule, the identification of Antoni A and B areas, and positivity of the tumor cells for S-100 protein. (7) The tumor in our patient met all these criteria.
Ideally, a neurilemmoma should be totally excised, but anatomic constraints sometimes make this difficult. (3,4,6) The preferred method is microlaryngeal endoscopic excision with either conventional microlaryngoscopy instruments or a C[O.sub.2] laser. An open approach may be necessary for larger lesions. In fact, surgeons should individualize the treatment of each laryngeal tumor, keeping in mind the need for maintaining mucosal integrity. Some authors feel that preoperative tracheotomy tracheotomy (trākēŏt`əmē), surgical incision into the trachea, or windpipe. The operation is performed when the windpipe has become blocked, e.g., by the presence of some foreign object or by swelling of the larynx. is mandatory for patients with larger tumors. (6) The preferred surgical approaches for removal of laryngeal neurilemmomas are the transhyoid approach, the laryngofissure approach, and the lateral pharyngotomy pharyngotomy /phar·yn·got·o·my/ (far?ing-got´ah-me) incision of the pharynx.
Incision of the pharynx. approach. The lesion in our patient was completely excised via a standard microlaryngoscopic technique. The airway was secured with an endotracheal tube that had a small diameter and therefore did not impede the excision. Minimal bleeding occurred during the procedure.
Although it is rare, neurilemmoma must be included in the differential diagnosis of laryngeal swellings.
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(3.) Takumida M, Taira T, Suzuki M, et al. Neurilemmoma of the larynx: A case report. J Laryngol Otol 1986;100:847-50.
(4.) Sanghvi V, Lala M, Borges A, et al. Lateral thyrotomy for neurilemmoma of the larynx. J Laryngol Otol 1999;113:346-8.
(5.) New GB, Erich JB. Benign tumors of the larynx. A study of 722 cases. Arch Otolaryngol 1938;28:841-910.
(6.) Meric F, Arslan A, Cureoglu S, Nazaroglu H. Schwannoma of the larynx: Case report. Eur Arch Otorhinolaryngol 2000;257:555-7.
(7.) Enzinger FM, Weiss SW. Benign tumors of the peripheral nerves. In: Enzinger FM, Weiss SW. Soft Tissue Tumors. St. Louis: Mosby; 1988:725-35.
Jonathan R. Newton, MRCS MRCS Member of Royal College of Surgeons.
Member of the Royal College of Surgeons ; Robert W. Ruckley, FRCS FRCS Fellow of the Royal College of Surgeons.
Fellow of the Royal College of Surgeons ; Ursula M. Earl, FRCP FRCP Fellow of the Royal College of Physicians.
Fellow of the Royal College of Physicians
From the Department of Otolaryngology (Dr. Newton and Dr. Ruckley) and the Department of Pathology (Dr. Earl), Darlington Memorial Hospital Darlington Memorial Hospital provides acute services for the area around Darlington, South Durham and parts of North Yorkshire. Its quality of services and use of resources were rated 'good' by the HealthCare Commission Ratings. , Sheffield, U.K.
Reprint requests: Dr. Jonathan R. Newton, 17 Queens Mansions, Queens Ave., Aberdeen AB15 6WA, UK. Phone: 44-7753-987-851; fax: 44-1224-554-569; e-mail: email@example.com