Laryngeal fibroma

One type of laryngeal tumor mass is laryngeal fibroma, a tumor made of connective tissue that is classified as a mesenchymal tumor.

Fibrous neoplasms of the larynx are detected quite rarely and, despite their benign nature, they can be locally aggressive, and under the influence of various unfavorable factors their malignant transformation is not excluded. [1]

Epidemiology

Among benign lesions of the larynx, tumors account for 26% of cases; the main patient population is male (men are affected six times more often than women) in the age range from 30 to 60 years.

Up to 70% of benign tumors are localized in the vocal cleft, 25% in the supraglottic and 5% in the oropharyngeal areas.

The remaining masses, according to clinical statistics, appear to be inflammatory pseudotumors (resulting from hyperplasia of lymphoid tissue or spindle cell proliferation with a marked inflammatory infiltrate).

Primary benign fibrous histiocytoma in the lower larynx (with localization from the vocal cords to the beginning of the trachea) occurs in only 1% of middle-aged patients with laryngeal tumors.

Causes of the laryngeal fibroma

Depending on the cause of fibromas of the larynx are divided into the main types: congenital and acquired. In the first case, experts believe that the supposed causes of the appearance of fibrous formations of this localization are genetically determined inclination of the organism, viral and bacterial infections of the future mother, as well as teratogenic effects during ontogenesis (intrauterine development), leading to mutation of the germ cell. [2]

In the second case, risk factors for laryngeal fibroma formation at the junction of the middle and anterior thirds of the vocal cords include:

• increased stress on the vocal cords due to the need to speak long and loud;
• smoking and alcohol abuse;
• irritation of the larynx by inhaled vapors, gases, fine substances (which is often associated with poor industrial or general environmental conditions);
• exposure to inhalant allergens;
• Long-standing inflammatory processes involving the larynopharynx, in particular chronic laryngitis, a chronic form of pharyngitis or catarrhal sore throat, among others;
• persistent nasal breathing disorder;
• Irritating effect on the laryngeal mucosa of acids of stomach contents due to gastroesophageal reflux in the presence of GERD - gastroesophageal reflux disease or extraesophageal reflux;
• chemical laryngeal burns;
• endocrine and systemic connective tissue diseases in the history.

Some medications, such as antihistamines (used for allergies) cause mucous membranes to lose moisture, which can cause further irritation and/or hypersensitivity of the laryngeal mucosa and vocal folds.

On the basis of histology, myo and elastofibroma can be distinguished, and soft or dense fibromas can be distinguished according to their consistency. Fibromas are also considered to be a type of fibroma laryngeal polyps.

In addition, very rare so-called desmoid fibromas include aggressively growing fibroblastic masses of unclear origin (with local infiltration and frequent recurrences). [3]

For more information see. - Benign tumors of the larynx

Pathogenesis

In most cases, laryngeal fibromas are solitary rounded masses (often pedunculated, i.e., with a "pedicle"), up to 5 to 20 mm in size, composed of fibroblasts of mature fibrous tissue (originating from embryonic mesenchyme) and located on the mucosal vocal folds (plica vocalis) within the larynx, commonly referred to as the vocal cords.

Explaining the pathogenesis of laryngeal fibroma formation, experts note the anatomical features and morphological characteristics of the tissues of the vocal folds. From above they are covered with multilayered squamous epithelium, below there is ciliated pseudostratified epithelium (which consists of mucinous and serous layers); deeper lies the submucosal basal membrane - the intrinsic lamina (lamina propria), formed by layers of macromolecules of lipopolysaccharides, as well as cells of loose connective tissue consisting of amorphous fibrous proteins and interstitial glycoproteins (fibronectin. Fibromodulin, decorin, versican, aggrecan).

Cellular communication with the extracellular matrix - to ensure the elastic biomechanical properties of the vocal fold during its vibration - is supported by basal plate hemidesmosomes and collagen and elastin fibers, with embedded fibroblasts, myofibroblasts, and macrophages.

Any tissue alteration activates cytokines and kinins, fibroblast growth factors (FGFs), platelet-derived growth factor (PDGF), etc., and as a result of activation of fibroblasts and macrophages, an inflammatory reaction develops and proliferation of connective tissue cells begins at the site of damage. And their induced proliferation leads to the formation of connective tissue tumor - fibroma.

Symptoms of the laryngeal fibroma

The first signs of a fibroma in the larynx are vocalization disorders: hoarseness, hoarseness, changes in the timbre of the voice and its strength.

As noted by otolaryngologists, the clinical symptoms of benign laryngeal tumors can range from mild hoarseness to life-threatening respiratory distress and most commonly manifest as:

• foreign body sensation or a lump in the throat;
• weakening (increased fatigue) of the voice during conversation;
• the onset of a dry cough;
• shortness of breath.

Complications and consequences

The more significant the size of the neoplasm, the higher the likelihood of complications such as:

• stridor (noisy breathing) and difficulty breathing - due to narrowing of the lumen of a particular part of the larynx;
• swallowing problems - dysphagia;
• Vocal cleft obstruction with loss of voice (aphonia).

Diagnostics of the laryngeal fibroma

Otolaryngologists record the patient's complaints, examine their larynopharynx and functional examination of the larynx.

Instrumental diagnosis - visualization of laryngeal structures with laryngoscopy and laryngeal stroboscopy, as well as CT and MRI - is a key diagnostic modality.

Diagnostic fibroscopy provides a sample of tumor tissue for histomorphological evaluation.

Differential diagnosis

Differential diagnosis is made with cyst, myxoma, fibroid and fibrosarcoma of the larynx, and carcinomas - laryngeal cancer.

Singing nodules or vocal fold nodules (nodose or fibrous chorditis, ICD-10 code J38.2), classified as diseases of the vocal cords and larynx and considered tumor-like polyposis of connective tissue, should also be differentiated. [4]

Treatment of the laryngeal fibroma

Only surgical treatment is performed for laryngeal fibroma.

Today, laryngeal fibroma removal is performed by electro and cryodestruction and, as the method of choice, by endoscopic laser treatment (using a carbon dioxide laser). [5]

That being said, some reports suggest that the recurrence rate of fibroma after laser surgery is around 16-20%. [6]

Prevention

You can prevent the formation of laryngeal fibroma by neutralizing risk factors such as smoking and alcohol abuse; you can also reduce stress on the vocal cords and use protective equipment when workplaces are polluted.

Respiratory infections should be treated in time, preventing them from becoming chronic.

Forecast

The prognosis of fibrotic neoplasms of the larynx is positive with respect to life, but the possibility of malignization should be kept in mind.