Fibroma of the larynx

One of the varieties of laryngeal tumor formations is the fibroma of the larynx - a tumor of connective tissue, which is referred to as mesenchymal tumors. 

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

Epidemiology

Among benign lesions of the larynx, tumors account for 26% of cases; the main contingent of patients are males (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 glottis, 25% in the supraesophageal and 5% in the peripharyngeal zones.

The remaining formations, according to clinical statistics, are inflammatory pseudotumors (formed as a result of hyperplasia of the lymphoid tissue or proliferation of spindle cells with a pronounced inflammatory infiltrate).

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

Causes of the fibroma of the larynx

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

In the second case, risk factors for the formation of a laryngeal fibroma 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 loudly and for a long time;
• smoking and alcohol abuse;
• irritation of the larynx with inhaled vapors, gases, fine substances (which is often associated with poor industrial or general environmental conditions);
• exposure to inhaled allergens;
• long-term inflammatory processes affecting the laryngopharynx, in particular,  chronic laryngitis , a chronic form of  pharyngitis  or catarrhal tonsillitis, etc.;
• persistent violation of nasal breathing;
• irritating effect on the mucous membrane of the larynx of acids from the contents of the stomach due to gastroesophageal reflux in the presence of GERD -  gastroesophageal reflux disease  or extraesophageal reflux;
• chemical  burns of the larynx ;
• endocrine and systemic connective tissue diseases in history.

Some drugs, such as antihistamines (used for allergies), cause loss of moisture in the mucous membranes, which can cause further irritation and/or sensitization of the larynx and vocal cords.

Taking into account histology, such types of formations as myo and elastofibroma can be distinguished, and according to their consistency - soft or dense fibromas. Laryngeal polyps are also considered a type of fibroma  .

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

For more details, see -  Benign tumors of the larynx

Pathogenesis

In most cases, laryngeal fibromas are solitary round-shaped formations (often pedunculated, that is, having a “leg”), up to 5 to 20 mm in size, consisting of fibroblasts of mature fibrous tissue (originating from the embryonic mesenchyme) and located on the mucous vocal folds ( plica vocalis) inside the larynx, usually called the vocal cords.

Explaining the pathogenesis of the formation of laryngeal fibroma, experts note the anatomical features and morphological characteristics of the tissues of the vocal folds. Above they are covered with stratified squamous epithelium, below is ciliated pseudostratified epithelium (which consists of mucinous and serous layers); the submucosal basement membrane lies more deeply - its own plate (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).

The connection of cells 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, interspersed with fibroblasts, myofibroblasts and macrophages.

With any tissue alteration, cytokines and kinins, fibroblast growth factors (FGFs), platelet growth factor (PDGF), etc. Are activated, and as a result of the activation of fibroblasts and macrophages, an inflammatory reaction develops and proliferation of connective tissue cells begins at the site of damage. And their induced reproduction leads to the formation of a connective tissue tumor - fibroma.[4]

Symptoms of the fibroma of the larynx

The first signs of a fibroma formed in the larynx are a disorder of voice formation: hoarseness, hoarseness, a change in the timbre of the voice and its strength.

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

• sensations of a foreign body or  coma in the throat ;
• weakening (fatigue) of the voice during the conversation;
• appearance of dry cough;
• shortness of breath.

Complications and consequences

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

• stridor (noisy breathing) and shortness of breath - due to narrowing of the lumen of a separate section of the larynx;
• problems with swallowing -  dysphagia ;
• obstruction of the glottis with loss of voice (aphonia).

Diagnostics of the fibroma of the larynx

Otolaryngologists record the patient's complaints, examine his laryngopharynx and  perform a functional examination of the larynx .

Instrumental diagnostics - visualization of laryngeal structures using  laryngoscopy  and  stroboscopy of the larynx , as well as CT and MRI - is a key diagnostic method.

Conducting diagnostic fibroscopy allows you to obtain a sample of tumor tissue for its histomorphological evaluation.

Differential diagnosis

Differential diagnosis is carried out with a cyst, myxoma, fibromyoma and fibrosarcoma of the larynx, as well as with carcinomas -  cancer of the larynx .

Singing nodules or  nodules of the vocal folds  (nodous or fibrous chorditis, code J38.2 according to MK-10), referred to diseases of the vocal cords and larynx, should also be differentiated and are considered tumor-like polyposis formations of the connective tissue.[5]

Treatment of the fibroma of the larynx

With fibroma of the larynx, only surgical treatment is performed.

To date, the removal of laryngeal fibroids is carried out by the method of electro and cryodestruction, and also - as a method of choice - by endoscopic laser exposure (using a carbon dioxide laser).[6]

At the same time, according to some reports, the level of recurrence of fibroids after laser surgery is about 16-20%.[7]

Prevention

It is possible to prevent the formation of fibroids of the larynx by neutralizing such risk factors as smoking and alcohol abuse; it is also possible to reduce the load on the vocal cords, and in case of gas contamination of industrial premises, use protective equipment.

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

Forecast

Regarding life, the prognosis of fibrous neoplasms of the larynx is positive, but the possibility of their malignancy should be borne in mind.