TITLE: Benign lesions on vocal cords causing hoarseness<=
br>
SOURCE: Grand Rounds Presentation, UTMB, Dept. of Otolaryngology
DATE: March 06, 2009
RESIDENT PHYSICIAN: Francisco Pernas, MD
FACULTY PHYSICIAN: Michael Underbrink, MD
SERIES EDITORS: Francis B. Quinn, Jr., MD
"This material was prepared by resident physicians in
partial fulfillment of educational requirements established for the
Postgraduate Training Program of the UTMB Department of Otolaryngology/Head=
and
Neck Surgery and was not intended for clinical use in its present form. It =
was
prepared for the purpose of stimulating group discussion in a conference
setting. No warranties, either express or implie=
d, are
made with respect to its accuracy, completeness, or timeliness. The material
does not necessarily reflect the current or past opinions of members of the
UTMB faculty and should not be used for purposes of diagnosis or treatment
without consulting appropriate literature sources and informed professional
opinion."
Introduction:
This chapter will focus on benign vocal cord les= ions that cause hoarseness. The objectives are to broadly define hoarseness, dis= cuss the anatomy and function of the larynx as well as discuss presenting signs, symptoms, physical exam, ancillary tests that may be obtained to attempt to ascertain a diagnosis It will mention general ca= uses of hoarseness and then discuss in depth benign lesions causing hoarseness. =
Hoarseness is has many definitions however the consensus is that it is an alteration in phonation. More specifically it is= a rough, abnormal harsh quality or the perception of voice with breathy or abnormal quality. Although hoarseness has an ICD-9 code it is not a disease= it is a symptom of a disease. Any patient with hoarseness of two weeks duratio= n or longer must undergo visualization of the vocal cords. There are many differ= ent causes of hoarseness, however these different processes result in the same effect of altered phonation. This topic will f= ocus on benign causes which is a very frequent presenting complaint
Anatomy:
The frame work of the larynx is composed of cartilage, it consists of the thyroid, epiglottic, arytenoids, and the corniculate. The corniculate and cuneiform cartilages stiffen the= aryepiglottic folds. The a= rytenoid cartilages articulate with the cricoid by means= of a true synovial joint. This joint allows two movements of the arytenoid cartilages – rotation and lateral gliding.
There are three groups of intrinsic laryngeal
musculature – the abductors, adductors, and tensors. The only a=
bductor
of the larynx is the posterior cricoarytenoid m=
uscle
and it is innervated by the recurrent laryngeal nerve. The adductors =
are
composed of the lateral cricoarytenoid muscle, =
interarytenoid muscle, oblique a=
rytenoid
muscles, and thyroarytenoid muscles. Innervation of the adductors is again supplied by the
recurrent laryngeal nerve. The tensors are composed of mainly the
Understanding the anatomy of the vagus nerve is important because branches of t= he vagus nerve are responsib= le for innervation of the larynx= . The vagus nerve has= three nuclei located within the medulla- nucleus ambiguous, dorsal nucleus of the vagus, nucleus of the tra= ct of solitarius. Nucleus ambiguous is the mo= tor nucleus of the vagus nerve. The efferent fibers of the dorsal (parasympathetic) nucleus innervate the <= span class=3Dspelle>involuntary muscles of the bronchi, esophagus, heart, stomach, small intestine, and part of the large intestine (to the splenic flexure). The efferent fibers of the nucleus = of the tract of solitarius= carry sensory fibers from the pharynx, larynx, and esophagus.
The va=
gus
nerve emerges from the skull through the jugular foramen. It has two
ganglia, the smaller superior ganglion and the larger inferior, or nodose, ganglion. The
The right vagus nerve passes anterior to the subc= lavian artery and gives off the right recurrent laryngeal nerve. This loops around= the subclavian and asce= nds in the tracheo-esophag= eal groove. It tends to run with the inferior thyroid artery for part of its co= urse before it enters the larynx just behind the cricothyroid joint. It may branch prior to thi= s with sensory fibers supplying sensation to the glottis and = subglottis. The left vagus does not give off its recurrent laryngeal nerve until it is in the thorax, where the left recurrent laryngeal nerve w= raps around the aorta just posterior to the ligamentum arteriosum. It then= ascends back toward the larynx in the TE groove. The vagus then continues on into the thorax and ab= domen contributing fibers to the heart, lung, esophagus, stomach, and intestines = as far as the descending colon.
Histology
The vocal fold was determined to be composed of
several layers by Hirano in 1974.
The most superficial layer is the epithelium which is pseudostratified squamous=
on the
superior and inferior surfaces of the cords and nonker=
atinized
stratified squamous on the contact surface of t=
he
cords. The middle layer, lami=
na propria, is composed of three parts, and will be desc=
ribed
from superficial to deep.
Physiology
The larynx has multiple functions. First, = it acts as a sphincter to close the airway during swallowing, preventing aspiration of food and liquids. This is phylogen= etically the oldest and perhaps most important function of the larynx. Larynge= al function is also essential for respiration, as it acts as the gateway for airflow. Additionally, the larynx plays an integral role in phonation. Finally, the larynx stabilizes the thorax by preventing exhalation. During coughing, lift= ing, and straining it compresses the abdominal cavity. At rest the cords f= orm a V-shaped space (the glottis), divided into the vibratory (membranous) and= nonvibratory (cartilaginous) portions. The vocal cord= s are divided into anterior, mid, and posterior thirds. With regard to phonation,= the vocal cords are divided into the upper vibratory lips and the lower vibrato= ry lips.
During phonation the lower margins of the true v= ocal folds separate first with formation of a volume of sub= glottic air. As the upper margins of the vocal folds separate a burst of air = is released known as the glottal puff. The lower fold then returns to midline, followed by the upper margin. This delay between closure of = the lower and upper margins of the fold is termed the phase delay. The mucosal wave consists of both a horizontal movement of the folds and a vert= ical undulation.
The body-cover theory helps explain this mucosal wave. It states that there are two layers of the vocal folds with different structural properties. The cover is composed of stratified = squamous epithelium and the superficial layer of the = lamina propria (Reinke’s space). The body of the fold is composed of the intermediate and deep layers of the lamina propria (vocal ligament), = which is more fibrous than the superficial layer. The muscular layer is the thyroarytenoid (vocalis) muscle. The cover is pliable, elastic, and nonmu= scular, whereas the body is stiffer and has active contractile properties that allow adjustment of stiffness and concentration of the mass. The mucosal wa= ve occurs primarily in this loose cover of the fold. Changes in stiffnes= s or tension in the fold alters the mucosal wave. As the stiffness in the = fold increases with contraction of the cricothyroid muscle, the velocity of the wave increases and the pitch rises. Mucos= al wave velocity also increases with greater airflow and greater subglottal pressure.
The pitch of voice is related to the fundamental frequency of vocal fold vibration (measured in hertz). The fundamental frequency of vocal fold vibration correlates with changes in vocal fold ten= sion and subglottal pressure. Contraction of t= he cricothyroid muscles, which correlates positively with vocal fold tension, is the main predictor of fundamental frequency, especia= lly at high frequency. Contraction of the thyroaryte= noid may change the tension of the vocal fold cover and body and affect the fundamental frequency also. Three physical properties of the vocal folds determine frequency of vibration – mass, stiffness, and viscosity&nbs= p;
The fundamental frequency of vocal fold vibratio=
n is
inversely proportional to its mass. Decreasing the mass increases the
frequency of vibration. This =
occurs
with thinning of the fold by longitudinal stretching (contraction of the
Vocal fold tension, or stiffness, is an important variable in the control of fundamental frequency at the mechanical level.&n= bsp; Vocal fold tension is affected by the contractile forces of the vocal fold musculature and the tissue characteristics of the vocal fold body, cover, a= nd the connecting fiber structure of the vocal folds.
Viscosity is inversely related to ease with whic= h the tissue layers slip over one another in response to a shear force. Increased viscosity of the vocal folds would require greater subglottal pressure to maintain the same vibratory characteristics. Therefore, hydration of the vocal folds has effect on the voice quality and ease of voice production.
Workup
Hoarseness is a non-specific symptom that can re= sult from a variety of disease processes ranging from a benign sessile polyp to potentially life-threatening carcinoma. Furthermore, hoarseness can b= e a manifestation of systemic disease that may affect the larynx. A thoro= ugh history and physical examination of the patient complaining of hoarseness is required in addition to visual inspection of the larynx. Fortunately,= a diagnosis can be made in most cases of hoarseness after the TVCs have been adequately examined. Keep in mind that any patient with hoarseness of= two weeks duration or longer should undergo visualization of the TVCs.
History
As always, obtaining a pertinent history is of u= tmost importance. The physician should determine the onset, duration, and severity of the dysphonia<= /span>. The larynx is also crucial in protecting the lower respiratory tract and is= a conduit of the upper respiratory tract. Therefore, the patient may present with coughing and choking episodes, aspiration, stridor, dyspnea, dysphagia, or odynophagia. Intubation history and previous head and neck trauma are crucial pieces of information. It is important to know if the patient has had any previ= ous laryngeal surgery or other head and neck surgery.
A specific vocal history is also important. = ; Many patients who present with vocal complaints have a disease entity that does = not warrant surgical treatment. Aside from onset, duration, variability, and pa= st vocal problems, history should include pertinent medical questions such as presence of seasonal allergies, history of reflux disease, life stress, diabetes, and medications. Many patients who present for an initial evaluation of voice complaints are unfamiliar with questions of vocal use a= nd hygiene. It is important for the physician to explain these concepts = to the patient during the questioning to facilitate accurate responses and edu= cate the patient. Questions should include voice demands at home and at wo= rk, recreational singing, and episodes of abuse i.e. sporting events. Smoking, water intake, caffeine intake, and environmental irritants are important questions about vocal hygiene.
Physical Examination
As with any complaint, examination begins with a= full head and neck exam searching for pathology which may reveal the cause of the patient’s dysphonia. A thorough and detailed examination of the larynx is required when a patient presents with= a voice related problem. The important features to consider when select= ing the laryngeal examination method are the ability to visualize the vocal tra= ct in a physiologic position, the image quality, magnification, cost of the procedure, equipment required, and the time and skill required to perform t= he evaluation.
When assessing a patients voice it is important = to consider the perceptual quality of voice, the frequency, loudness, hypo ver= sus hypernasality, stridorous= versus breathy, harsh versus tremorous and note any ar= rests in phonation.
The indirect mirror exam is the initial procedur= e used to view the larynx. It is quick, inexpensive, and only requires a mir= ror and external light source. Gross abnormalities may be detected quickly but subtle abnormalities may be missed. Disadvantages include the lar= ynx not being in physiologic phonation position (the tongue is extended and the larynx is elevated), some anatomic features limit the exam, and a hyper-reflexive gag is present in 5-10% of patients.
Rigid laryngeal endoscopy is performed in the of= fice using 70 or 90 degree telescopes passed through the mouth to obtain images = of the larynx and pharynx. These are the highest quality images obtainab= le and offer excellent magnification. These endoscopes and their light sources are usually less expensive than high-quality flexible endoscopes.&n= bsp; The patients are viewed in a nonphysiologic pho= nation position similar to the indirect examination. Anatomic factors and hyper-reflexive gags can again limit the results.
The flexible laryngoscope is probably the tool t= hat most otolaryngologists rely upon in the evaluation of the dysphonic patient. It is the sole method that allows examination of the nasopharynx, palate, larynx, and pharynx in a near physiologic position. It can be performed relatively easily even in patients with hyper-responsive gags and pediatric patients. It takes slightly more time to perform than the indirect mirror exam and requires a relatively expensive scope and light source. These disadvantages are = more than outweighed by the information obtained and ability to record the image= s on video.
Videos=
trobolaryngoscopy
(VSL) should be performed whenever possible. It allows for dynamic
assessment of the vocal folds. The features most helpful in the
diagnostic process include the vocal fold closure pattern, vocal fold vibra=
tory
pattern, and the mucosal wave of each vocal fold during phonation. The
stroboscopic flash can be synchronous or asynchronous with the frequency of
vibration. A synchronous pattern will give the appearance of a motion=
less
cord. When the flash is slightly asynchronous, if gives the impressio=
n of
slow motion. With this view, =
the
physician is able to differentiate between functional voice problems and th=
ose
caused by subtle structural abnormalities. The physician is able to
evaluate symmetry of movement, aperiodicity,
Ancillary tests can and should be ordered howeve= r they type of ancillary test ordered should be determined by the history, physical findings sign and symptoms. If autoimmune disease is suspected to be the ca= use of the hoarseness a complete autoimmune panel should be ordered such as ANA, RA, ACEi, CRP, ESR, c-ANCA and p-ANCA. If a thy= roid mass or goiter is thought to be causing hoarseness a thyroid panel and neck ultrasound should be ordered. For infectious etiologies a CBC and perhaps a FTA-ABS should be sought. Of course in the presence of any neck masses a CT scan should be requested. If a neurologic cause is suspected as the cause o= f hoarsness and CT head or MRI should be obtained and f= inally if a chest mass is thought to be causing hoarseness a chest xray or CT chest should be obtained. Although not routinely ordered a modified barium swallow can be obtained if dysphagia is also a complaint.
Using a systemic approach will lead to more accu= rately diagnosing the cause of hoarseness and will decrease the chance of missing a diagnosis.
Benign Vocal Fold Mucosal Disorders
There are a variety of benign mucosal fold disor= ders that result in hoarseness. So= me of the more common lesions are polyps, nodules, varices and ectasias, cysts, granu= lomas, polypoid corditis (= Reinke’s edema), granular cell tumors, laryngocele and papillomatosis.
Vocal Nodules
Vocal fold nodules can vary in size, contour, symmetry, and color. They alw= ays occur bilaterally. Nodules ar= e a diagnosis that should be reserved for lesions of proven chronicity. The majority of these lesions resu= lt from vocal abuse or inappropriate vocal use. Nodules occur in the anterior two-= thirds of the vocal folds. Vibration= of the vocal folds that is too forceful or prolonged results in vascular conge= stion with edema in the submucosa. Long-term voice abuse will result = in prolonged edema, which can eventually result in hyalinization in the superficial lamina propria. Ultimately, this will lead to the formation of nodules. Given t= he predominately behavioral etiology of vocal nodules, it is fitting that voice therapy is the primary modality of treatment. Surgical excision becomes an optio= n for persistent nodules that continues to impair the patient’s voice (according to the patient) after a minimum voice therapy trial of three mon= ths.
Vocal Fold Cysts
Vocal fold cysts arise in the superficial lamina=
propria and present in a variety of sizes. It is possible for cysts to be att=
ached
to the vocal ligament. Smaller
cysts are sometimes freely suspended in the superficial lamina propria. The
most prominent epidemiologic finding is a history of vocal overuse. These cysts are either classified =
as
mucus retention cysts or epidermoid inclusion c=
ysts
depending on their origin. Mu=
cus
retention cysts arise from plugged mucus glands, while epidermoid
inclusion cysts result from keratin accumulation in the subepithelial
layer. V=
ideostroboscopy
typically reveals characteristic asymmetric oscillation of the mucosa due to
the stiffness in the area of the cyst.&nbs=
p;
Patients without a history of voice abuse are more likely to have mu=
cus
retention cysts and may be scheduled for surgery without further work-up.
Vocal Polyps
Vocal fold polyps present in an array of sizes, shapes, and composition. They= may be sessile or pedunculated and they may be vasc= ular, fibrotic, or mixoid. The underlying cause is usually tr= auma to the superficial lamina propria and microvasculature. Polyps most common location are in the middle musculo-membranous region of the vocal fold. This is because the shearing and collision forces on the superficial lamina propria are greatest in this region. = The involvement and replacement of the superficial lamina = propria with these lesions is highly variable.&nbs= p; Videostroboscopy will help with the eval= uation in determining the involvement of the superficial lamina propria. The primary treatment for vocal po= lyps is surgical excision.
Vocal Fold Varices and
Varices and ectasias of the vocal folds are the result of microvascular trauma within the superficial lamina
Vocal Fold Granulomas
Vocal fold granulomas result from traumatic disruption of the mucosa.&n= bsp; These granulomas are classified as being contact granulomas or intubation granulomas depending on their etiology. Contact granulomas result from chronic coughing or throat clearing combined with acid reflux into the posterior larynx. Intubation granulomas are the result of intubation, endolaryngeal surgery affecting the arytenoids perichondrium, rigid bronchoscop= y, or other direct laryngeal manipulations.&n= bsp; The majority of granulomas are found in = the arytenoids region. Primary treatment includes removing the inciting cause if applicable, antireflux management, and voice therapy. Surgery should be a last resort as postoperative recurrence frequently occurs.
Papillomas
Squamous papillomas are the most common benign neoplasms seen by laryngologists. Papillomas are most commonly located in the musculo-membra= nous region. These lesions are ext= remely variable in size and shape. T= he microspot CO2 laser is the most widely accepted manag= ement for papillomas in the larynx due to its inheren= t hemostatic properties. The recurrence rate for these lesions is quite high, estimated at seventy percent for excision of chronic patients.
Laryngocele
While the exact mechanism of=
laryngocels
is unknown it is a disorder of the saccule.
A perhaps more clearly documented although uncom=
mon
cause for saccular cysts is laryngeal carcinoma,
which causes obstruction of the saccular orific=
e.[63]
Laryngocele formation also may be facilitated b=
y the
congenital presence of an abnormally large saccule. I
have also seen saccular cyst months or years af=
ter
excision of a large supraglottic carcinoma with=
the
laser, leaving remnants of the saccule buried.
Potential complications of laryngoceles are
Polypoid Corditis
Polypoid corditis, or Reinke’s edema, presents as extensive swelling of the superficial lamina propria. The swelling is usually located on= the superior surface of the musculo-membranous vocal fold. Smoking, laryngo-pharyngeal reflux, and vocal abuse are required components to develop this condition.<= span style=3D'mso-spacerun:yes'> Laryngeal examination reveals pale, fluid filled compartments attached to the superior surface and margins of t= he fold. Smoking cessation is encouraged for patients with polypoid corditis. Antireflux precautions should be started, as well as = voice therapy. Surgical intervention should be offered when the voice remains objectionable to the patient. The main technique used to improve voicing is reduction of the superficial lamina propria= .
Granular cell tumor
Half of all granular cell tumors occur in the he= ad and neck, the most common site being the tongue and 10% occurring in the larynx. The average age of a patient presenting with a granular cell tumor is 37 ye= ars of age. They arise from Schwann cells and as such stain positive for S-100 = and vimentin. They demonstrate pseud= oepitheliomatous hyperplasia and because of this they can be frequently confused with squamous cell carcinoma by a pathologist. The treatme= nt of granular cell tumors is endoscopic excision or an open approach for larger tumors and for recurrences. E= ven when incompletely excised they only recur in 10% of patients.
Conclusion
The symptom of hoarseness is a common complaint = that the otolaryngologist encounters. A detailed and accurate history is essential in formulating a differential diagnosis of possible causes. Examination of the larynx provides the most useful information with regards to the actual diagnosis. Often times, lesions of the true vocal folds are benign. Decisions regarding treatment depe= nd on the type of lesion and the end result desired by the patient. Overall, the goal should be = to preserve the normal anatomy as much as possible so that the optimal vocal outcome can be achieved.
References:
Portions contributed directly from Garrett Hauptman Hoarseness presen= tation on April 13, 2005 and Reddy, Shashidhar S, “Vocal Cord Paralysis and Vocal Cord Medializati= on,” Quinn Grand Rounds Archive, Apr 28, 2004; and Katzenmeyer, Kevin, “Laryngeal dysfunction, hoarseness, and videost= roboscopy,” Quinn Grand Ro= unds Archive <http://www.utmb.edu/otoref/Grnds/GrndsIndex.html> , Oct = 24, 2001.
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