Schwannoma of the true vocal fold: a rare diagnosis.Abstract
Schwannomas of the larynx are rare, benign, slowly growing tumors. When they do occur, they are most often isolated in the aryepiglottic folds or false vocal folds. When a tumor originates in the larynx, it typically causes hoarseness and a globus sensation. As the tumor expands, it may cause dyspnea, 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. , and possibly asphyxiation asphyxiation /as·phyx·i·a·tion/ (as-fix?e-a´shun) suffocation; the stoppage of respiration.
Oxygen starvation of tissues. as a result of the mass effect, In this article, we report an unusual case of a schwannoma of the true vocal fold in a young woman.
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. laryngeal tumors are rare, accounting for approximately 0.1% of all benign tumors of the larynx. (1) These tumors arise from the cells of the peripheral nerve, including Schwann's cells, perineural cells, and fibroblasts, and they can produce schwannomas and neurofibromas. Schwannomas arise from neural crest-derived Schwann's cells; they can originate in any peripheral or cranial nerve except the olfactory and optic nerves, which lack Schwann's cells. Approximately 45% of schwannomas arise in the head and neck region, most often in the parapharyngeal space. (2,3) Schwannomas are well-circumscribed and encapsulated submucosal submucosal /sub·mu·co·sal/ (-mu-ko´sal)
1. pertaining to the submucosa.
2. beneath a mucous membrane. tumors that are extrinsic to nerve fascicles and thus are easily separated. Recurrence can follow an incomplete resection, but malignant transformation is extremely rare. (4) In this article, we describe a case of an unusual laryngeal schwannoma of the true vocal fold in a young woman.
In December 2001, a 26-year-old woman with no otherwise significant medical history presented to the office with a 7-year history of hoarseness. She reported that her hoarseness had begun following a severe upper respiratory tract infection upper respiratory tract infection URI Infectious disease A nonspecific term used to describe acute infections involving the nose, paranasal sinuses, pharynx, and larynx, the prototypic URI is the common cold; flu/influenza is a systemic illness involving the URT . Over the course of the 7 years, the hoarseness would become aggravated by alcohol consumption, smoking, and voice straining, although her overall voice quality did not change. She denied any dyspnea, dysphagia, odynophagia, stridor, or globus sensation.
Flexible fiberoptic laryngoscopy revealed the presence of a large submucosal mass in the right vocal fold; the mass appeared to be cystic in nature (figure 1). Both vocal folds were mobile, and no significant airway compromise was detected. Computed tomography (CT) identified a cystic lesion in the area of the right vocal fold (figure 2). The lesion was contained within the laryngeal framework. No cartilage destruction was evident.
The patient underwent direct suspension microlaryngos-copy and biopsy. Consistent with the findings of the fiber-optic examination, the right vocal fold was seen to bulge into the glottic glot·tic
1. Of or relating to the tongue.
2. Of or relating to the glottis.
pertaining to (1) the glottis, or (2) the tongue. space. No evidence of subglottic extension was observed. A sickle knife was used to make a linear incision along the right true vocal fold, and microflaps were dissected medially and laterally. Blunt dissection revealed a thick, encapsulated, soft-tissue mass. The tumor was completely excised. The patient was extubated following the procedure, and she remained stable in the recovery room. Histopathologic examination revealed that the lesion was a benign laryngeal schwannoma (figure 3).
Two weeks postoperatively, the patient reported that her voice had progressively improved and that her hoarseness was minimal. Follow-up flexible fiberoptic laryngoscopy revealed that the right vocal fold was healing well, erythema was minimal, and edema was absent. The fold was immobile and fixed in the paramedian position. At the 4-month follow-up, fiberoptic examination revealed that the right fold was almost fully mobile and the airway was patent. No sign of recurrence was evident, and the patient's voice had improved markedly.
Schwannomas are rare tumors that are usually found in the false vocal folds and aryepiglottic folds. (5) To the best of our knowledge, only 10 other cases of a schwannoma of the true vocal fold have been documented in the literature. (2,6) These tumors are believed to arise from 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 . (1) Schwannomas affect patients in all age groups, and they occur predominately in women. (2) Because these lesions grow slowly, patients often report an insidious onset of symptoms that gradually progresses over the course of years. Patients typically present with hoarseness and a globus sensation; they may later develop dyspnea and stridor secondary to the mass effect of the lesion, In 1997, Gardner et al reported a fatality secondary to asphyxiation, but death from laryngeal schwannoma is extremely rare. (7)
Laryngoscopic examinations have revealed that these tumors often produce a submucosal bulge that obscures the view of the true vocal folds. (4) In our patient, preoperative CT of the neck and laryngoscopic findings were more suggestive of a cystic lesion than a soft-tissue tumor. This illustrates that the diagnosis of schwannoma is based more on histology than on the clinical picture. Schwannomas typically have three histologic characteristics: (1) they are encapsulated, (2) they feature Antoni A and/or Antoni B growth patterns, and (3) they are S-100-positive. (8) The Antoni A growth pattern is characterized by the classically described Verocay bodies, which are an arrangement of spindle cells in compact clusters with palisading nuclei and pooled cytoplasm. The Antoni B growth pattern is characterized by edema and a loose arrangement of spindle cells in a myxoid myxoid /myx·oid/ (mik´soid) mucoid.
Containing or resembling mucus; mucoid.
myxoid adjective 1. matrix. (9)
Schwannomas must be distinguished from neurofibromas because the latter are more likely to recur and more likely to undergo malignant transformation (10% of cases). (10,11) Neurofibromas can develop singly or multiply; multiple lesions characterize neurofibromatosis Neurofibromatosis Definition
Neurofibromatosis (NF), or von Recklinghausen disease, is a genetic disease in which patients develop multiple soft tumors (neurofibromas). These tumors occur under the skin and throughout the nervous system. type 1. (10) Unlike schwannomas, neurofibromas are intertwined within the nerve fascicles, which makes surgical removal difficult. The differential diagnosis of a laryngeal schwannoma includes laryngeal cyst, laryngocele, adenoma, chondroma chondroma /chon·dro·ma/ (kon-dro´mah) pl. chondromas, chondro´mata a benign tumor or tumor-like growth of mature hyaline cartilage. , lipoma lipoma: see neoplasm. , and neurofibroma neurofibroma /neu·ro·fi·bro·ma/ (-fi-bro´mah) a tumor of peripheral nerves due to abnormal proliferation of Schwann cells.
n. . (12) Direct laryngoscopy and biopsy are required for diagnosis. However, an overly aggressive endoscopic biopsy may cause scarring and preclude a complete resection of the tumor. With this in mind, Cohen cohen
(Hebrew: “priest”) Jewish priest descended from Zadok (a descendant of Aaron), priest at the First Temple of Jerusalem. The biblical priesthood was hereditary and male. et al recently advised that the biopsy be taken at a site away from any area vital to the voice. (13)
Because laryngeal schwannomas are radioresistant, surgical excision is the treatment of choice. It is important to remove the tumor completely because of the risk of a rapid recurrence that could lead to airway compromise. (4) The size of the tumor dictates the surgical approach. An endoscopic approach is sufficient for smaller tumors, but larger tumors may require an external approach (e.g., lateral pharyngotomy pharyngotomy /phar·yn·got·o·my/ (far?ing-got´ah-me) incision of the pharynx.
Incision of the pharynx. or midline thyrotomy) to achieve complete tumor removal while preserving laryngeal function and the overlying overlying
suffocation of piglets by the sow. The piglets may be weak from illness or malnutrition, the sow may be clumsy or ill, the pen may be inadequate in size or poorly designed so that piglets cannot escape. mucosa.
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(2.) Zbaren P, Markwalder R. Schwannoma of the true vocal cord true vocal cord
See vocal cord.
true vocal cord Anatomy A fold of laryngeal mucous membrane that produces sound when taut and vibrating . Otolaryngol Head Neck Surg 1999; 121:837-9.
(3.) Sanghvi V, Lala M, Borges A, et al. Lateral thyrotomy for neurilemmoma of the larynx. J Laryngol Otol 1999; 113:346-8.
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(7.) Gardner PM, Jentzen JM, Komorowski RA, Harb JM. Asphyxial asphyxial
pertaining to or emanating from asphyxia.
asphyxial respiratory failure
respiratory failure manifested by dyspnea with alternating apnea and gasping respiration before death. death caused by a laryngeal schwannoma: Acase report. J Laryngol Otol 1997;111:1171-3.
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(9.) Cotran RS, Kumar V, Collins T, Robbins SL, eds. Robbins Pathologic Basis of Disease. Philadelphia: W.B. Saunders, 1999:1352-5.
(10.) Cummings CW, Montgomery WW, Balogh K Jr. Neurogenic tumors of the larynx. Ann Otol Rhinol Laryngol 1969;78:76-95. (11.) Elias MM, Balm AJ, Peterse JL, et al. Malignant schwannoma of the parapharyngeal space in von Recklinghausen's disease von Reck·ling·hau·sen's disease
von Recklinghausen's disease Neurofibromatosis, type 2 Neurology An AD condition characterized by cafe-au-lait skin spotting and pendulous fibrous tumors. : A case report and review of the literature. J Laryngol Otol 1993; 107: 848-52.
(12.) Martin PA, Church CA, Chonkich G. Schwannoma of the epiglottis epiglottis (ĕp'əglŏt`ĭs): see larynx. : First report of a case. Ear Nose Throat J 2002;81:662-3.
(13.) Cohen S, Sinacori JT, Courey MS. Laryngeal schwannoma: Diagnosis and management. Otolaryngol Head Neck Surg 2004;130: 363-5.
Jennifer Taylor, BA; Marc Stiefel, MD; Steven Y. Park, MD
From the Department of Otolaryngology, New York Medical College New York Medical College is a center for graduate medical education located in Westchester County, a suburb half an hour north of New York City. This private university comprises the School of Medicine, which grants the M.D. (Ms. Taylor), and the Department of Otolaryngology, New York Eye and Ear Infirmary The New York Eye and Ear Infirmary was founded on August 1, 1820 by Edward Delafield and John Kearney Rodgers, both graduates of the New York College of Physicians and Surgeons. (Dr. Stiefel and Dr. Park), Brooklyn.
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