Pathology of lower throat cancer

2021-02-01 12:00 AM

Type of lymphoma Malpighi carcinoma: This type is very rare, visible to the naked eye like a strawberry, thus very similar to an adenocarcinoma.

Outline

Throat cancer in Vietnam is more common than laryngeal cancer, but treatment results are worse because the initial clinical symptoms are relatively discreet, most of the patients coming to the examination are in a late stage.

Define

The International Association against Cancer (UICC) of lower throat cancer is cancer that occurs in 3 regions: the sinus, the region behind the funnel and the posterior wall of the throat.

Epidemiology and disease

Incidence rates are very different across countries and even regions and provinces within the same country are also different. In Vietnam, cancer of the lower throat ranks 3rd after nasopharyngeal cancer, nose and sinus cancer in the scope of ENT cancer.

About age: most common from the age group 50-65 (accounting for about 75%), before 50 and after 65 years old accounts for about 25%.

About gender: Throat cancer is mainly found in men than women (ratio 2/1).

In terms of the disease, not clearly defined: some factors are most commonly associated with alcohol and tobacco addicts, in addition factors that irritate the throat mucosa such as gases, vapors, dust the occupation of people exposed to these substances.

Histology

Micro: Because the mucous membrane covering the lower throat is the Malpighi epithelium, the majority of throat cancers are Malpighi carcinomas.

General: two common forms are common: ulcerative morphology, infiltration accounts for 85%, damage starts from the mucosa and penetrates deeply to the underlying tissues (gland, muscle layer, membrane, cartilage ...) and layered morphology accounts for about 10-15%. The latter is quite special: it has small or seedy buds, is not smooth but not infiltrating, so it is difficult to distinguish from a chronically inflamed mucosa.

Other clinical forms of throat cancer

These patterns are uncommon, but they are the source of errors in diagnosis and treatment such as:

Type of carcinoma of sarcomas: clinically, this type is very easy to remind us of a sacoma, the general view is a lesion with a markedly defined, protruding and stalks, peduncle, common in the membrane part of the sinus or posterior funnel ring, while the pharynx and larynx are less common. Microscopically, the tumor cells are no longer epithelial, spindle cells, large, scattered as a fibroblast or muscle sarcoma. Some believe that this cancer is more common after radiation therapy.

Malignant rice seeds: rare, very differentiated hyperplasia, thick, fibrous and less infiltrative, slow growing, less running into the lymphatic system, less susceptible to chemicals. Microscopic diagnosis is also difficult because the malignant lesions are usually deep, so biopsy requires many pieces.

Type of lymphoma Malpighi carcinoma: This type is very rare, visible to the naked eye like a strawberry, so it is very similar to an adenocarcinoma, so it must be stained and cut several times in the central tumor tissue.

Type of dome differentiated carcinoma (UCNT): microscopic very similar to the type of UCNT of cancers of the dome, this type is only found on the surface of the sinus cavity and also very rare in throat cancer.

Clinical

Sinus cancer

A common type of throat cancer.

Symptom

The first is most common with unilateral difficulty swallowing or discomfort in one throat, especially when saliva is swallowed. After several weeks or months, the feeling of difficulty swallowing gradually increases, the symptoms of swallowing throbbing pain in the ears become clearer, sometimes spitting up bloody mucus. Gradually difficulty speaking, due to the tumor has begun to spread into the throat wall, larynx or due to edema.

Clinical examination

Tumors confined to one part of the sinus cavity: tumors in the anterior angle, often ulcerative form, edematous infiltration, glottic mobility in general is normal. Tumors in the inner wall (or the wall of the pharynx, larynx) are usually located below the laryngeal funnel splint, this type is often infiltrated, so the half of the larynx is often fixed. Tumors in the outer wall (or the lower side of the throat) are commonly seen as infiltrative or proliferative. The type of tumor of this area usually accounts for 50% of the tumor's localized form, so conservative surgery can be performed.

The tumors have spread to the sinus walls: most of the sinus has been infiltrated in the form of an infiltrative ulcer, surrounded by edema. Fixed half of the larynx, which can only identify the tumor through direct laryngoscopy combined with tomography of the larynx. 

Large tumors have spread beyond the sinus area: the stage is widespread of cancer of the throat or larynx; the tumor has spread to both the lower throat and larynx. Clinical examination is difficult to determine whether the tumor origin is from the lower throat or larynx. So, it is known as cancer of the larynx of the larynx or larynx, or lower throat cancer. To know the exact primary tumor, it is necessary to carefully ask the history (clinical symptoms of the digestive or respiratory system appear first) combined with the histological diagnosis of the patient after surgery as well as the injury. in place at surgery. In this case, when palpable, there is a loss of laryngeal filtering sound of the spine due to swelling of the posterior pharyngeal wall and thickening of the posterior border of the cartilage.

Assessment of tumor spread: based on the International Association of Cancer Classification (UICC - 1979) classification of TNM as follows:

T (Tumor): Primary tumor.

Tis: Pre-invasive carcinoma.

T0: no sign of primary tumor.

T1: Tumor is localized in an anatomic site.

T2: The tumor has spread to another location of the lower throat or into a contiguous area, but the larynx has not been fixed.

T3: Like T2 but half of the larynx is fixed.

T4: The tumor has spread to cartilage, bone, or soft tissue.

Tx: there are not enough conditions to identify a primary tumor.

N (Node): ancient node.

N0: lymph node was not palpable.

N1: Unilateral palpable nodule, but still mobile.

N1a: lymph node cell but not evaluated for cancer metastasis.

N1b: lymph node cell but assessed to have cancer metastasis.

N2: lymph node opposite or bilateral but still mobile.

N2a: to evaluate the lymph node that has not had cancerous metastasis.

N2b: to evaluate lymph nodes for metastatic cancer.

N3: fixed lymph nodes.

M: (Metastasis): distant metastasis.

M0: There is no distant metastasis.

M1: distant metastasis has occurred.

Detection of cervical lymph nodes: common is unilateral cervical lymph node, while bilateral lymph node or opposite lymph node only accounts for 5-8%. The most common lymph nodes are grouped in the middle 1/3 of the carotid trough (corresponding to the group of ganglia on the shoulder blade muscle, while the regression group is rarely palpable.

Subclinical

Pathological anatomy: biopsy to confirm the diagnosis and treatment protocol. It can be done at the initial examination, especially the proliferation, warts, if superinfection or edema is treated with a course of antibiotics, anti-edema 4-5 days, then biopsy. If the patient is examined by endoscopy, biopsy always, endoscopy can perform anesthesia or anesthesia depending on the specific case, can use a flexible bronchoscope (if possible) or a rigid bronchoscope.

X-ray: In order to have accurate information, it is necessary to take a CT Scan scan of the lower throat and esophagus to be able to assess the depth of infiltration such as the pituitary fossa, the glottis and early detection. thyroid cartilage damage.

Diagnosis: in general, a diagnosis of sinus cancer is not very difficult except in the following cases that need to be differentially diagnosed with edema on one side of the funnel splint or part of the sinus membrane due to an injury or foreign object an ulcerative tuberculosis lesion of the sinus, bilateral sinus sputum congestion due to narrowing of the esophagus segment, a tumor in the neck that compresses the mouth of the sinuses.

Cancer after the funnel ring

A type of cancer arising from the posterior mucosa of the larynx that is the mucosal area covering the aortic cartilage, the intercostal muscles and the ring cartilage. Histologically the majority remains a differentiated type of Malpighi carcinoma. In general, the common form is ulcerative ulcer and ulcerative. Tumors often encroach on the inner wall and anterior angle of the sinus, but most commonly spread down the esophagus mouth. At this stage, it is often difficult to detect where the tumor is coming from (from the mouth of the esophagus or from the back of the larynx), it is more rare to spread upward to the posterior sinus margin and often in the late stage. . The most common symptom is difficulty swallowing, but this symptom is not noticeable and progressive, so the patient is often ignored.

Indirect microscopy is difficult to identify lesions because often mild edema and the posterior funnel ring is usually slightly raised, sometimes difficult to distinguish between lesions of the posterior larynx or hypopharynx. Therefore, it is necessary to examine by endoscopy. In the early stage, the cervical lymph node is often undetectable.

Diagnose

X-ray: Contrast tilt-neck film to determine the starting point and whether the tumor in the posterior laryngeal wall has spread to the mouth of the esophagus. If conditions tomography or CT Scan helps to accurately assess lesions.

Direct laryngoscopy (endoscopy helps to clearly see the damage, especially the mouth of the esophagus).

Staging of the disease (TNM): according to the International Association against Cancer (UICC).

T (Tumor): Primary tumor. 

Tis: Pre-invasive cancer.

T0: the primary tumor is not found.

T1: Cancer is localized behind the funnel ring, has not yet penetrated nearby tissue.

T2: The tumor has spread to the sinus or posterior hypopharynx, has not yet penetrated neighboring tissue (not fixed).

T3: The tumor has spread to the larynx or muscles anterior to the spine.

N and M are classified as sinus cancer.

Oral esophageal cancer

Oral esophageal cancer is mostly circular invasive on the boundary between the lower throat and esophagus. Many authors believe that it belongs to the lower throat rather than the esophagus.

This type of cancer usually spread in the following directions:

Spread into the pharynx, the larynx is rarer and often in the late stage, immobilize the vocal cords (only about 10%).

Down the mucosa to the lower throat and down the esophagus or to the front into the trachea, also into the thyroid.

Metastatic cervical nodules are also common and are often palpable in the late stage. Appearance of palpable metastatic cervical lymph nodes on first examination. The most common is the lower cervical ganglia followed by the regression group, while the mediastinal lymph node is rarer.

Mechanical symptoms

The signs begin to be very discreet, often appearing only in the middle of the throat and slowly progressing, sometimes choking, so the patient pays little attention.

Indirect screening

It is difficult to determine or only detected in the lower pharyngeal area with accumulation of sputum, sometimes with edema if there is an ulcer in the upper part of the lesion. There are cases that can see the lesion of one of the throat walls (or the area after the funnel ring) spread down the mouth of the esophagus. In this case, it is difficult to determine the starting point of the lesion. It is necessary to palpate the neck area for two purposes: to detect the cervical nodes in the low region and along the tracheal axis, to check whether the tracheal axis is still mobile or fixed with the anterior cervical spine.

Test

X-ray of the lower throat area, tilted neck scan with contrast material, straight scan and if possible to take CT Scan, on tilted neck film, it can be seen that the soft tissue behind the ring cartilage has thickened, if this space is wider, The posterior pharyngeal wall is clearly separated from the pharynx above and the back of the trachea below. The edge of the posterior cartilage ring is unevenly jagged. On the straight film, the contrast image of the posterior cartilage is irregular, but the most difficult is to determine the upper margin of the tumor.

Treatment of throat cancer

Surgical methods for throat cancer

Specify the type of surgery depending on the lesion of the tumor and lymph nodes, the following surgical methods are usually used:

Cut out lower throat, total larynx.

Cut off a lower throat, larynx.

Cut half of the larynx, lower throat.

Cut half of the larynx, lower throat on the glottis.

Radiation treatments

The general trend of many authors in the world is to combine postoperative radiation, field rays include the lower throat, larynx and lateral ganglion chains. The upper limit of the field-ray passes through the lower margin of the outer ear canal, the anterior limit is the skin of the anterior neck (the anterior part of the trachea can be shielded), the lower limit is the mouth of the esophagus and the posterior limit is the margin. behind the mastoid bone. Lower cervical ganglia can use the upper beam. Located near the spinal cord, the number of rays should not exceed 45Gy. Normally, the number of rays in tumors of the lower throat, larynx and cervical lymph nodes must reach 65-70Gy, the rays are evenly scattered every day 2Gy, each week from 10-12Gy. If the lymph nodes are not infiltrated, 45-50Gy rays can be used.

In general, the results of prolonging life expectancy for patients from 3-5 years reach 25-35%, some live more than 10-15 years, but achieve a low rate of 10-12%. Most deaths are due to local recurrence or lymphadenopathy and often accompanied by distant metastasis (more commonly to the lung or bone), in some cases with a second cancer. Therefore, patients who have been treated should be examined and monitored periodically every 2 months for the first 3 years and every 4-6 months in the following years. In the first 3 years 6 months, lung scan is done once.