Vocal fold lesions are noncancerous growths that develop on the vocal folds, structures housed within the larynx, or voice box. These lesions, which include nodules, polyps, and cysts, are a common cause of voice problems. When these abnormal growths interfere with the precise, wave-like vibration of the vocal folds, they significantly alter voice quality.
Anatomy and Definition of Vocal Fold Lesions
The vocal folds are two flaps of tissue situated in the larynx, which function as the source of sound production. To generate sound, a process called phonation, air forced from the lungs causes the vocal folds to rapidly vibrate. This vibration modulates the airflow into acoustic energy, which the vocal tract then shapes into recognizable speech.
The structure of each vocal fold is layered, consisting of a muscle body, a ligament, and a soft outer covering called the epithelium and lamina propria. This layered composition allows for the delicate mucosal wave motion necessary for clear voice. A vocal fold lesion is defined as a benign, abnormal growth or mass that occurs within or along this covering.
The presence of a lesion introduces physical mass or stiffness to the fold, which disrupts the normal, symmetrical vibration. Any structural change prevents them from closing completely or vibrating uniformly. This interference with the vibratory pattern results in the voice sounding rough, breathy, or strained.
Classification of Common Lesion Types
The three most frequently encountered benign vocal fold lesions are nodules, polyps, and cysts. Vocal fold nodules are characterized as bilateral, callus-like formations. They typically appear at the midpoint of the membranous part of both vocal folds, which is the area of highest impact stress during voicing.
Vocal fold polyps usually present as a unilateral growth, and they tend to be softer and more blister-like in appearance. Polyps can vary significantly in size and shape, sometimes appearing on a small stalk, and they often contain an increased supply of blood vessels compared to nodules. The size and location of the polyp determine the severity of the resulting voice disturbance.
Vocal fold cysts are encapsulated, sac-like structures located deeper within the vocal fold tissue. These growths may be near the surface or closer to the underlying vocal ligament. Cysts can arise from the entrapment of tissue lining or from the plugging of a mucous-secreting gland beneath the surface.
Primary Causes and Warning Signs
The leading cause of vocal fold lesions, particularly nodules and polyps, is chronic voice misuse or abuse. Actions like excessive talking, speaking too loudly, screaming, or cheering all place significant strain on the vocal mechanism. Professions that demand high vocal output, such as teaching, sales, or singing, carry an increased risk for developing these growths.
Several other factors can irritate the folds and contribute to lesion development, including chronic acid reflux, known as Laryngopharyngeal Reflux (LPR). Irritants like smoking, frequent coughing, and chronic throat clearing also increase inflammation and the likelihood of injury.
The most common warning sign that a lesion is present is persistent hoarseness or a rough, scratchy voice quality. Patients often experience vocal fatigue, where the voice tires easily or requires increased effort to produce sound. Other symptoms can include:
- Breathiness
- A loss of vocal range
- Pitch breaks
- A feeling of general discomfort or pain in the neck area
Medical Assessment and Treatment Pathways
A specialist will conduct a comprehensive assessment that begins with a detailed history of the voice problem and speaking habits. To confirm the diagnosis and determine the lesion type, the doctor uses a specialized visualization tool called a stroboscope during a rigid laryngoscopy. This technique uses flashing light synchronized with the vocal fold vibration to create the illusion of slow-motion movement.
Laryngeal stroboscopy allows the doctor to assess minute details, such as the mucosal wave and the symmetry of the fold vibration, which are disrupted by the lesion.
For vocal fold nodules, the preferred initial treatment is non-surgical, centered on voice therapy guided by a speech-language pathologist. Voice therapy focuses on correcting the underlying vocal technique and improving vocal hygiene to reduce trauma and allow the lesions to diminish.
In contrast, vocal fold cysts and many polyps often require surgical intervention because they do not respond adequately to voice therapy alone. The surgical procedure, known as phonomicrosurgery, involves the delicate removal of the growth using microsurgical instruments. This surgery aims to preserve the fine, layered structure of the vocal fold to restore the mucosal wave and achieve optimal voice quality.