Pathology of laryngeal cancer

2021-02-01 12:00 AM

The vast majority of laryngeal cancers are carcinomas, while very rare, connective cancer (sarcoma) accounts for only about 0.5%.

Outline

Laryngeal cancer is common cancer in Vietnam, if, within the ear, nose and throat area, laryngeal cancer ranks 4th after nasopharyngeal cancer, nasopharyngeal cancer and lower throat cancer.

Based on the statistics of many countries around the world, laryngeal cancer accounts for about 2% of all common cancers.

Referring to laryngeal cancer is only a tumour located in the larynx, including the hypothermic, laryngeal, Morgagni larynx, vocal cords and hypopharynx, and other tumours beyond the above locations belong to the type of throat cancer.

The vast majority of laryngeal cancers are carcinomas, while very rare connective cancer (sarcoma) accounts for only about 0.5% (Leroux Robert and Petit), so this section mainly deals with laryngeal carcinoma.

Factors related to pathogenesis

Up to now, the main cause of the disease has not been found out, but it is mentioned that the following factors are related to pathogenesis:

Tobacco: Many people consider it an important factor contributing to the development of laryngeal cancer as well as lung cancer.

Stimulating factors: microclimate, occupational effects (exposure to gases, dust, chemicals ...) or chronic laryngitis (the premise of cancer).

Gender: Mainly common in men, accounting for over 90%, many authors believe that women are less likely to suffer from this disease due to less exposure to factors related to disease than men.

About age: common in the age group: 50-70 years (72%), from 40-50 years old less (12%). Particularly for women, if this disease is at an earlier age.

With forms of chronic laryngitis such as hyperplasia, leukoplakia is susceptible to cancer, so these bodies are also known as a precancerous state.

The benign tumours of the larynx are also most susceptible to cancer, with a high proportion of papilloma of the larynx.

Pathological anatomy

General

Common three forms are as follows:

Hyperplastic morphology: papilloma-like appearance, in some cases a stalked polyp.

Deep-down infiltration pattern: mucosal appearance appears intact, sometimes nipple-like, mucosa of this region is pushed up and mobility is limited.

The ulcer pattern is usually irregular, bleeding easily to the touch. But the most common is a mixture of both proliferative and ulcerative, or both ulcerative and infiltrating.

Micro

The majority of laryngeal cancers belong to the type of carcinoma of the sliced, prickly keratinocytes, accounting for 93% or the sub keratosis, followed by the basal cell, intermediate and adenocarcinoma type.

Less differentiated tumours are rare in laryngeal cancer. Clinically, this type progresses rapidly but is sensitive to radiation.

Clinical

Location and spread of the tumour

Cancer of the glottis (upper layer) or vestibular larynx.

Usually arises at the same time in both the vocal cords and the lower surface of the vocal cord. It will spread rapidly to the opposite side, the serous funnel splint and the epidural cartilage in the diseased side, often enlarged due to infiltrates or oedema. In the early stages, the base of the ventricular vocal cords and vocal cords are normal. It is difficult for the naked eye to accurately assess the penetration into the deep, so it is necessary to have conventional tomography or, at best, a CT Scan scan to evaluate the true anterior pit.

Cancers that arise from the Morgagni ventricle are usually proliferative or ulcerative and usually begin at the base of the ventricles or vocal cords, but generally, the ulcer spreads very quickly into the surrounding areas, down the vocal cords, and down the glottis. , upon the laryngeal bandages, out the thyroid cartilage sometimes even funnel cartilage.

Laryngeal (vocal cord) cancer is the most common type and usually, the tumour is limited to the upper surface or free margin of vocal cord if detected early.

Hyperplasia can be seen; infiltrates or ulcers are rare.

Because difficult to pronounce symptoms appear early, patients often come to the clinic earlier than other cancers. Vocal cord cancer progresses relatively slowly, usually after months, sometimes a year, because the submucosa of the vocal cords is usually dense and the lymphatic membrane is very sparse. The tumour gradually spreads from the upper surface of the mucosa to the deep layer and then begins to rapidly grow down the lower glottis and up the larynx.

Carcinoma of the vocal cord usually stays on one side for a long time before spreading to the opposite vocal cord.

Subglottic cancer: less common than the two types above, but examination and detection is also more difficult. To confirm, direct laryngoscopy and tomography are required.

This type is often infiltrated and usually below the vocal cords, so it is shielded by cartilage wings, so it is difficult for the tumour to spread out. The tumour usually begins at the underside of the vocal cords and spreads down the mucosa, infiltrates deep, but the free margin of the vocal cords is normal, so if a biopsy is transient, it is rarely tumour lesions that require direct laryngoscopy, sometimes even opening thyroid cartilage (thyrotomy).

Cancer usually grows rapidly to the opposite side, crosses the anterior laryngeal edge, then spreads below the ring cartilage. There are cases where the tumour spreads through the ringing membrane or infiltrates the ring cartilage surface. Commonly, the tumour spreads up and behind the funnel-shaped joint, causing the vocal cords to be fixed

Clinical symptoms of laryngeal cancer

Clinical symptoms differ depending on the location of cancer, including when it appears.

Mechanical symptoms

Hoarseness is increasing and leading to difficult, hoarse, and lossy pronunciation.

Shortness of breath appears and increases, although this symptom has been present for a long time, but in a mild degree, the patient can adapt, but then appear each episode of dyspnea, most serious when stimulation leads to spasm. larynx, sometimes accompanied by a secondary superinfection (acute flu due to flu, radiation edema), severe difficulty breathing.

Cough: is also a common but discreet and irritating symptom, sometimes with a spasmodic cough.

Pain occurs only when the tumour has spread to the upper edge of the larynx, especially when the tumour has been ulcerated. Pain often spreads in the ears and aches when swallowing.

In the late stage, it appears difficult to swallow and choke on food, secretion into the airway, causing choking coughs. At this stage, the whole condition is also affected.

Clinical examination

In early-stage vocal cord carcinoma, the tumour is usually localized on one side of the vocal cords in the form of a small or slightly infiltrated bud and is common in the anterior half of the vocal cords or anterior edge. Cell mobility of the vocal cords at an early stage, if the proliferation, is not affected much, but if it is infiltrative, the mobility is slightly limited. The evaluation of vocal cord mobility is very meaningful in indications for treatment.

U in the subglottic, first of all, the mobile vocal cords are restricted and then spread over the midline, so it is easy to confuse with a tumour of the glottis.

tumours in the adenoma are rarely detected at an early stage, the edema of the ventricular bandage covers the larynx, thick, firm mucosa, then the ulcer spreads quickly to the splint of the pharynx and sinus. So, tumours in this area are often seen in the late stage under the form of infiltration or proliferation, sometimes accompanied by ulcers and spread into the anterior fossa.

If laryngeal cancer is left untreated, usually lasting only a year or 18 months, death is often caused by acute asphyxiation, bronchitis complications, exhaustion, or massive bleeding.

Metastasis of laryngeal cancer

Neck: depending on the location of the tumour, the metastatic cervical lymph node is also different because it depends on the lymphatic system of that area. This lymphatic system usually has two distinct networks of demarcation: one in the glottis, one in the lower glottis, these two networks are delimited by the vocal cords. The adrenal network consists of lymphatic vessels from the vestibular larynx pouring into the lymphoid body, passing through the lateral part of the basement membrane and the end of the upper carotid ganglia. The subglottic network is also quite rich, though less dense than the glottis. As for the boundary region, the vocal cords, the lymphatic system is very small, scattered along the vocal cords, then connected to the network of the larynx or subglottic. Therefore, adrenal cancer usually has early metastasis of the cervical lymph node, while subglottic cancer has metastasis later. These regional lymph nodes are usually deep, making it more difficult to detect the clinic.

Far less common metastasis of laryngeal cancer is less common than that of lower throat cancer, according to many authors, the most common metastasis to the lung (4%) followed by spine, bone, liver, stomach, oesophagus (1.2%). Until now, it has not been determined what factors are related between primary tumour and distant metastasis to the lungs and bronchi, so it is important to check for lung lesions before treatment for laryngeal cancer. strength needed.

Diagnose

Implementing the quadrants

Laryngeal cancer, if diagnosed early and treated in time, it can be cured with an increasing rate. Different from adenocarcinoma and hypopharynx, due to inconspicuous initial symptoms. So, the patient is easy to ignore, does not go to the doctor, and cancer of the glottis (vocal cord) often appears early, the symptoms are difficult to speak, hoarseness, so the patient should go to the doctor earlier.

In cases where there is a lesion on one side of the larynx, the lesions are still very localized, the vocal cords are somewhat abnormal, they must be monitored and performed necessary tests to rule out cancer.

Differential diagnosis

Hypertrophic chronic laryngitis, with a contact ulcer in the apex or a desert mucosa.

In the early stage, clinically it is necessary to differentiate from laryngeal tuberculosis (laryngitis or tuberculosis form). The posterior infiltrate is very similar to a TB lesion, but very little TB lesions originate from this site.

With a lupus lesion, commonly seen in the vocal cord and vestibular larynx but characterized by the coexistence of many morphologies at the same time (both ulcerative, infiltrated, and scarred) It's not that difficult to judge.

Syphilis stage III, the erectile stage is also easy to confuse with infiltrating cancer in the larynx or larynx. If in the ulcer stage, it should be differentiated from vestibular tumour or cancer of the throat or larynx. The ulcer is uneven, volcanic-shaped, around a snake, red like the colour of beef, painless is characteristic of an ulcer.

Unmovable unilateral vocal cords should be distinguished from a regression or funnel-ring arthritis.

With benign tumours, it is necessary to distinguish from a polyp, a papilloma because these tumours are susceptible to cancer, especially elderly people, men. Therefore, in these cases, it is necessary to periodically examine, follow up and it is necessary to do multiple biopsies.

In the late stage, due to symptoms such as loss of sound, difficulty breathing, swallowing difficulty, fixed cervical lymph nodes ... is clear, so diagnosis is not difficult, especially when laryngoscopy, the tumour has quite clear, large, occupied most of the larynx and in some cases spread to nearby tissue.

Classify

According to the classification of the International Association against Cancer (UICC): based on the mobility of the vocal cords, the appearance of cervical lymph nodes, distant metastasis to sort by the TNM system

T (tumour): Primary tumour.

Adenocarcinoma:

Tis: Pre-invasive tumours.

T1: A localized tumour on the inferior of the vocal cord, either one side in a coronary aortic splint, or one side of the ventricle, or one side of the vocal cyst.

T2: Lymphoma has spread to the ventricular or vocal cords.

T3: u is like T2 but lead to vocal cords.

T4: U is like T3 but has spread to the sinus, posterior cartilage, lingual groove, and base of the tongue

U in the glottis:

Tis: Pre-invasive tumours.

T1: u on one side of the vocal cords, the vocal cords are still mobile.

T2: u in both vocal cords, normal or fixed moving vocal cords.

T3: The tumour has spread to the subglottic or has spread to the upper glottis.

T4: as T1, T2, T3 but has broken thyroid cartilage spread to the skin, sinus or ring cartilage.

U in the subglottic:

Tis: Pre-invasive tumours.

T1: tumour is localized on one side of the subglottic.

T2: The tumour has spread to both sides of the subglottic.

T3: The cyst in the hypotonic has spread to the vocal cords.

T4: Such as T1, T2, T3 but has spread into the trachea, to the skin or the area after the ring cartilage.  

N (Node): ancient node.            

N0: lymph nodes are not palpable.

N1: unilateral lymph node mobile.

N1a: evaluate the lymph node without metastasis.

N1b: to evaluate lymph nodes for metastasis.

N2: opposite or bilateral lymph nodes remaining mobile.

N2a: to evaluate the lymph nodes without metastasis.

N2b: to evaluate the lymph node with metastasis.

N3: fixed lymph nodes.

M (Metastasis): distant metastasis.            

M0: There is no distant metastasis.

M1: distant metastasis has occurred.

Treatment

The most effective treatment method is to combine surgery with postoperative radiation. Up to now, there have been 3 main methods: pure radiation, simple surgery and combined surgery with radiation. Those who arrive at an early stage, are localized, do not have metastatic cervical lymph nodes, can be operated with surgery or pure radiation.

Surgical methods

In principle, there are two types, conservative surgery or partial laryngectomy, after this surgery, the patient can pronounce breathing according to the natural physiological pathway, while radical surgery or total laryngectomy, after this surgery, the patient must breathe through the trachea hole directly to the skin of the neck and pronounce without a natural physiological path (oesophagal voice, through a speech aid or through surgery to pronounce).

Depending on the location, the spread of the tumour as well as the condition of the metastatic cervical lymph node, surgical methods are chosen.

Cut off part of the larynx.

Huet-style vocal removal surgery.

Alonso-style transverse laryngectomy.

Bar wire surgery.

Leroux-Robert style lateral laryngectomy.

Surgery to remove the frontal larynx.

Hautant-style laryngectomy.

Complete laryngectomy.

Treatment methods with radiation therapy

Up to now, the use of radiation sources to treat malignant tumours is one of the most important and basic measures, especially tumours within the head and neck area. Radiation therapy has many different methods, but there are the following main measures:

Treatment of radiation therapy alone.

Radiation therapy combined with surgery can be before or after surgery or an alternate combination, radiation-surgery-radiation therapy.

Other treatments for laryngeal cancer

In addition to the two basic and most effective methods in the treatment of laryngeal cancer mentioned above, for the past 10 years, some authors, mainly Western European countries, and the United States have coordinated chemotherapy. but the results are still debating.

Results of treatment for laryngeal cancer in Vietnam

Vocal cord cancer, if detected early and treated in time, can be completely cured, reaching the rate of 80%. Therefore, some authors also refer to vocal cord cancer as a "benign cancer" in order to emphasize the chronic treatment results of this cancer. On the other hand, it is also to remind physicians in general, especially Ear, Nose and Throat physicians in particular, to have a high sense of responsibility, to examine and closely monitor suspicious cases, if omitted, to concede one. laryngeal cancer, especially laryngeal cancer, must be considered as a treatment error because this type of cancer appears relatively early, the detection is also easy, convenient, does not require much complex and expensive technical equipment.

For other laryngeal cancers that are located in the larynx that have not spread to the lower throat, the treatment results are increasingly high (prolonging the life span of more than 5 years reaching over 45%).

Prevention

Many reports at international conferences have said that smoking is one of the factors related to lung cancer as well as laryngeal cancer. Therefore, it is necessary to widely propagate among the people and through state measures to prevent smoking and tobacco addiction. On the other hand, it is necessary to pass the mass media to disseminate basic knowledge about this type of cancer so that the sooner the patient can be examined, the higher the effect is. For specialist physicians, to avoid misdiagnosis in laryngeal cancer.