Salivary Glands Definition By Medical
Saliva glands definition is the three glands located in the mouth and function to form saliva (saliva) as a fluid that helps digestion in the mouth and throat. Saliva contains enzymes that start the process of digesting food chemicals. In addition, saliva contains antibodies and other chemicals that protect the mouth and throat from infection.
There are two groups of salivary glands based on their size, namely the major and minor salivary glands. Based on its location, the major salivary glands can be divided into:
- Parotid gland. The parotid gland is the largest salivary glands located in the front of the ear. The emergence of tumors and cancer in the salivary glands often occur in the parotid gland, which is about 7 out of 10 cases.
- The submandibular glands. The submandibula gland is smaller than the parotid gland and is located at the bottom of the jaw. This gland secretes saliva from under the tongue. About 1-2 of 10 cases of salivary gland tumors occur in the submandibular glands and half may be cancerous.
- Sublingual gland. The sublingual gland is the smallest salivary gland located at the bottom of the mouth on either side either left or right. Cases of tumors and cancers of the sublingual gland are rare.
In addition to the three major salivary glands, there are many minor salivary glands located in the mouth and too small to be seen through the naked eye. The locations of minor salivary glands include the lips, tongue, palate, cheeks, nose, sinuses, and larynx. The appearance of tumors in minor salivary glands is very rare, but if there is a tumor, tend to be malignant.
Generally, the doctor will examine the type of salivary gland cancer that occurs in patients and provide grading (level / level) to estimate whether the cancer will spread or not. The division of salivary gland cancer levels is as follows:
- Level 1, is a low-grade cancer that signifies that cancerous tissue looks similar to normal tissue. At this stage, the cancer will grow slowly and have a great chance of being cured.
- Level 2, is a middle-level cancer that signifies the growth of cancer cells that are more different from normal tissue.
- Level 3, is a cancer with the highest level and indicates that cancer tissue is very different from normal tissue, and tend to spread rapidly. Cancers at this level are less likely to be cured than those with levels 1 and 2.
In the salivary glands, there are various types of cells that converge and form tissues and glands. Based on the type of cells that experience malignancy, salivary gland can be divided into:
Mucoepidermoid carcinoma. This type of cancer is the most common salivary gland cancer. Mucoepidermoid carcinoma often occurs in the parotid gland, but can sometimes appear on the submandibular gland or in the minor salivary glands in the mouth. This type of cancer is generally a cancer level 1, but can increase to cancer level 2 or 3. Cancer level 1 has a higher likelihood of cure than cancer level 2 or 3.
Adenoid cystic carcinoma. This type of cancer often appears as a level 1 cancer if viewed using a microscope and has a slow growth. Adenoid cystic carcinoma can spread to neural networks around the salivary glands so it is quite difficult to dispose of completely. Remains of cancer tissue that is not wasted can reappear after cancer treatment is done, sometimes up to several years after treatment.
Adenocarcinoma. Adenocarcinoma is a cancer that occurs in cells that secrete saliva (glandular epithelial cells). Some types of adenocarcinomas that can appear in the salivary glands are as follows:
- Asinic cell cancer. Most asinic cell cancers occur in the parotid glands that tend to occur at a young age than the elderly. Acidic cell cancer mostly appears as cancer with a low malignancy, but can spread to nearby tissues.
- Low-grade polymorphic adenocarcinoma (polymorphous low-grade adenocarcinoma / PLGA). This type of cancer is a cancer with a low level of malignancy that occurs in the minor salivary glands in the mouth. PLGA’s cancer generally grows slowly and can be cured easily.
- Non-specific adenocarcinoma (NOS). This type of cancer often appears in the parotid gland and minor saliva, but is difficult to classify as specific adenocarcinoma. This type of cancer can appear as cancer levels 1-3.
Mixed malignant tumor. Mixed malignant tumors in the salivary glands are mostly a type of carcinoma ex adenoma pleomorphis. This type of cancer develops from benign tumors of salivary glands called pleomorphic adenomas. In addition to ex pleomorphic adenomas, there are also called karsinosarkoma or mixed tumors that metastasize.
Cancer of other salivary glands. Some other types of salivary salivary glands that are rare include:
- Basal cell adenocarcinoma
- Clear cell carcinoma
- Adenocarcinoma sebacea
- Sebaceous lymphadenocarcinoma
- Adenocarcinoma of mucin cells.
Causes of Saliva Cancer
Like other cancers, salivary gland cancer occurs as a result of DNA changes in salivary gland cells. DNA changes in these cells are referred to as DNA mutations. Cancer is generally caused by mutations in two types of genes, namely oncogenes and gene suppressor tumors. Oncogenes are part of the DNA that triggers cells to grow and divide. Gene suppressor tumors are genes that work in opposition to oncogens, which slows growth and cell division. The emergence of cancers that cause uncontrolled cell growth may result from DNA mutations, either on oncogenes or gene suppressor tumors. DNA mutations in oncogens occur when the oncogene is activated causing the cell to grow and split uncontrollably. While DNA mutations in tumor suppressor genes occur if the gene is damaged so that cell growth can not be inhibited.
Salivary gland cancer is generally not a hereditary factor. DNA mutations that cause salivary gland cancer are usually acquired after birth. Sometimes these DNA mutations occur suddenly without any outside factors. However, in some cases, salivary gland cancer has specific external causes such as exposure to radiation from the outside or exposure to chemical compounds.
Some things that can increase a person’s risk of salivary gland cancer are as follows:
- Age. The risk of salivary gland cancer in a person increases with age.
- Man. The risk of salivary gland cancer in men is higher than in women.
- Exposure to radiation. Radiation exposure due to radiotherapy on the head or neck may increase a person’s risk of developing salivary glands. In addition, radiation exposure due to occupational risk may also increase the risk of salivary gland cancer in a person.
- Family history. Having a family history of cancer of the salivary glands may increase a person’s risk of developing the disease. However, most patients do not have a history of salivary gland cancer in the family.
- Smoking habits and drinking alcohol. Both tobacco and alcohol allegedly can increase the risk of salivary gland cancer in a person, although the mechanism is not known clearly.
- Unhealthy diet. A little fiber content and high levels of animal fat in everyday foods can increase the risk of salivary cancer in a person. However, these risk factors still need to be studied further.
- Exposure to hazardous chemicals in the work environment. Some studies have found that certain materials such as nickel dust, silica dust, asbestos, residual rubber production, mining chemicals can increase the risk of salivary gland cancer.
- Virus. Some viruses that infect humans may increase the risk of salivary gland cancer. Examples are the HIV virus and Epstein-Barr. As for the HPV virus, although it is a major cause of some cancers in the neck, it is not certain whether it can also increase the risk of salivary gland cancer.
- Skin Cancer History The risk of developing salivary glands in people who have had squamous cell cancer is higher than those who do not have a history.
Symptoms of Salivary Gland Cancer
Some of the symptoms of salivary gland cancer that generally appear in patients are as follows:
- A lump or swelling that occurs in the mouth, cheeks, jaw, or neck. Swelling in the area near the salivary glands can be a major marker of cancer. However, not every swelling can be ascertained as cancer. Some cases of swelling in the area are caused by benign tumors, saliva stones, or infections of the salivary glands.
- Pain in the mouth, cheeks, jaw, ears, or neck that happens continuously.
- There is a difference in the size of the cheek or jaw between the left and right.
- Numbness or stiffness on some facial muscles.
- The weakened facial muscles.
- Having problems opening your mouth wide.
- Discharge from the ear.
- It’s hard to swallow food and drink.
These symptoms may also arise from benign tumor gland (benign tumor) or other conditions. However, if experiencing these symptoms should be consulted immediately to the doctor in order to make the initial diagnosis so as to facilitate the next medical action.
Diagnosis of Salivary Gland Cancer
The steps to diagnose the presence or absence of salivary gland cancer in a person include the following:
Check medical history. The doctor’s first step in diagnosing is to check the patient’s medical history. The doctor will inquire and analyze the associated symptoms of salivary gland cancer as well as the timing of the symptoms. In addition, doctors will check for risk factors that increase the appearance of cancer to patients.
Physical examination. After checking the medical history, the doctor will perform a physical examination to recognize the symptoms of salivary gland cancer. Physical examination will focus on the areas of the face, mouth, ears, and jaws to determine the presence of lumps and enlarged lymph nodes around the face. The doctor will also check the weakness of the facial area and surrounding muscles. If needed, the patient will be referred to an ENT doctor for a more detailed examination of the symptoms of salivary gland cancer.
Physical examination is generally done by palpation method (touch and emphasis) to check the lump in the face area. Palpation can also predict malignant tumor. Benign tumors generally feel like a lump hard enough when massaged by hand. The degree of lump violence felt through palpation will increase with tumor malignancy or cancer. Palpation can also detect swollen lymph nodes around the salivary glands that can be a sign of the spread of cancer cells.
Scanning. Various scans can be used to diagnose salivary gland cancer. Through the scanning, doctors will be able to know the area of cancer, the spread of cancer, and the effectiveness of cancer treatment. Scanning methods that can be done are as follows:
- Photo Rontgen. To diagnose salivary gland cancer, X-rays can be used on the mouth, jaw, and teeth so that cancer sites are known. In addition, X-rays can be used in the chest area to determine whether the cancer has spread or not.
- CT Scan. CT scan is a method of scanning using X-rays in more detail. In the diagnosis of cancer, CT scan is used to show details of body tissues and internal organs. By using CT scan, can know the size, shape and position of cancer. CT scans can also help detect enlarged lymph nodes around the cancer and find out if the cancer has spread to other organs. The scanning process using CT scans is assisted by injecting contrast material into the body to produce a better picture.
- MRI. The purpose of MRI scanning is almost the same as that of a CT scan, which is to show a detailed overview of tissues and organs. The working principle is to use magnetic waves and radio waves to produce images of internal organs and certain diseases. The contrast material commonly used at the time of MRI scanning is gadolinium. By using MRI, doctors can determine the location of the cancer more accurately and distinguish benign tumors with malignant tumors. Also, just like a CT scan, MRI can describe the lymph nodes around the enlarged cancer.
- PET scan. Unlike scanning using the MRI or CT scan method, the PET scan will detect abnormal cellular activity. If the MRI or CT scan of the cancer tissue will be distinguished from its size, the PET scan of the cancer tissue will be differentiated based on its higher activity. The materials used in PET scans are generally radioactive sugars (sugar type FDG).Because cancer cells have higher activity than normal cells, the radioactive sugars in the cancer area will be absorbed more rapidly than the sugar in the normal cell area. Special cameras will be used to show the differences in radioactive sugar absorption as a marker of cancer area.
- Ultrasound examination (ultrasound). This test uses sound waves that are reflected by the body to produce internal organ images. The ultrasound location used to detect salivary gland cancer is usually in the neck region.
Biopsy. Methods of cancer diagnosis using biopsy provide more accurate results than other methods. Biopsy method is done by taking samples of body tissue suspected as a cancer and then examined with a microscope. Biopsy is divided into several methods based on how to obtain the desired network, namely:
- Smooth needle biopsy (fine needle aspiration). A fine needle biopsy is performed by taking body tissue using a fine needle without surgery. The patient will be given local anesthesia and the tissue will be taken as usual. The doctor may perform a fine needle biopsy if unsure whether the lump in the facial area is a benign tumor, malignant tumor, or inflammatory swelling. Sample tissue taken using fine needle biopsy should be sufficient for analysis to produce an accurate diagnosis. If the diagnosis result using a fine needle biopsy is not very accurate, more extensive biopsy methods can be performed.
- Incisional Biopsy. An incision biopsy is performed by performing small incisions in the tumor to take more tissue than using a fine needle biopsy. The tissue samples are then taken to a laboratory for examination using a microscope.
Salivary gland cancer is a rare disease in humans. Therefore, doctors usually do not recommend to screen cancer screening without any symptoms in the patient. In addition, due to the location of cancer that is easily observed, salivary gland cancer is quite easy to find and diagnosed at an early stage.
Division Stage of Salivary Gland Cancer
Classification of cancer stages indicates the spread of cancer in the patient’s body. Classification of the stage of cancer plays an important role in determining the appropriate and effective treatment, and predict the cure of patients from cancer. There are two cancer stage division systems, namely the TNM system and the Stage I-IV system. The division of cancer based on the TNM classification system is as follows:
- T (Tumor). Indicates the size of the primary cancer and whether it has spread to surrounding tissue or not. Cancer size is written with the numbers 0-4 that indicate tumor malignancy and X which means tumor malignancy is not certain.
- N (Nodes). Indicates whether the cancer has spread to the lymph nodes (lymph node) around the cancer or not. The size of the spread of cancer is written with the numbers 0-4 which indicates the spread of cancer and X which means the rate of spread of cancer can not be ascertained.
- M (Metastasis). Indicates whether the cancer has spread to other parts of the body or not (secondary cancer). Metastasis spread size is written with the numbers 0-1.
The division of malignancy of cancer based on stage I-IV system can be explained as follows:
- Stage I. Show that the cancer is still small, approximately no more than 2 cm and has not spread to tissue around the cancer. In stage I, the cancer has not spread to the lymph nodes near the cancer or spread to other organs.
- Stage II. Shows that the cancer has grown to more than 2 cm, but there has been no spread. In stage II, the cancer has not spread to local lymph nodes or to other organs.
- Stage III. Shows that the cancer has enlarged beyond approximately 4 cm and has spread to tissues around the cancer. In some cases, stage III cancer has spread to the local lymph nodes. But usually at this stage, there has been no spread either to the local lymph nodes or to other organs.
- Stage IV. At the start of stage IV (stage IV A), the cancer has spread to the tissues around the cancer as well as the local lymph nodes, but not yet to other organs. At the end of stage IV (stage IV B), cancer cells have spread to nearby tissues, lymph nodes, and spread to other organs.
Treatment of Salivary Gland Cancer
After a diagnosis of cancer and the determination of the stage of cancer, the doctor will provide treatment to patients. Factors that determine the type of salivary gland cancer treatment in a person include:
- Type of salivary gland cancer suffered
- Stage of cancer
- The spread of cancer
- Depth of cancer based on microscope observation
- The effect of this type of treatment on the ability to speak, swallow, and chew the patient
- Patient health conditions in general.
Some methods of treatment of salivary gland cancer that can be done is as follows:
Surgery. Surgery is the most effective method for removal of salivary gland cancer, especially in the parotid gland cancer because most salivary gland cancers occur in the parotid gland. Surgery to remove the parotid gland is called parotidectomy.
There are two types of parotidectomy: superficial parotidectomy and total parotidectomy. Superficial parotidectomy is performed if the cancer occurs only on the surface of the parotid gland and bypasses the part. The wedges on the superficial parotidectomy are minimized to maintain the facial nerve and do not interfere with facial muscle movement. Total patotidectomy is performed if the cancer has spread to most of the parotid tissue, so that the removal of the entire parotid gland. If the cancer has spread to the tissue around the parotid, the tissue is also removed to remove cancer cells to the maximum extent possible, including neural networks.
If the cancer has spread to the local lymph nodes, it is necessary removal of the lymph nodes to prevent the spread of cancer. The method of removal of lymph nodes is called lymphadenectomy or neck dissection. In addition to the removal of lymph nodes, sometimes required removal of surrounding tissues, such as muscle tissue, nerves, blood vessels, and connectors.
The side effects of surgery are generally postoperative nerve tissue damage. Patients given surgical cancer treatment may lose control of facial muscles. In addition, the side effects of surgery can lead to Frey syndrome that causes sweaty facial areas when chewing food. Frey’s syndrome can be overcome through additional surgery or drugs.
Radotherapy. Radiotherapy uses high-energy rays to kill cancer cells and slow its growth. Radiotherapy can be used as a primary cancer treatment in conjunction with chemotherapy. In addition, radiotherapy can be used as an adjunct therapy after surgery, to prevent cancer reappear. Generally for the treatment of salivary gland cancer is used external radiotherapy rays. The source of high-energy rays for radiation can come from both X-rays and radioactive neutron rays. X-rays are the most widely used type of radiotherapy, while neutron rays are a new breakthrough in cancer treatment. Neutron rays are thought to be more effective in treating cancer, but produce more side effects than radiotherapy using X-rays. Side effect of radiotherapy is the most common is the reduction of the production of saliva so that the mouth becomes dry. Other side effects of radiotherapy include:
- Dry mouth and throat
- Difficult to swallow
- Lack of tongue sensitivity
- Bone pain and damage
- Increases problems with teeth.
Chemotherapy. Chemotherapy is a therapy using anticancer drugs given by intravenous or oral. Chemotherapy is not too often used in treating salivary gland cancer, except in patients who already have stage IV cancer (metastasis). Chemotherapy is commonly used in conjunction with radiotherapy for the treatment of radiotherapy in salivary gland cancers more effectively. The doctor will give chemotherapy to the patient for 3-4 weeks along with radiotherapy. Side effects that may arise from chemotherapy are:
- Dry mouth
- Hair loss
- Loss of appetite
- Nausea and vomiting
- Increased risk of infection
- Bruising or bleeding due to lack of platelets
After surgery to remove cancer, in some cases reconstructive surgery is required. Reconstructive surgery is needed to maintain the function of organs around the cancer, such as the mouth and jaw, in order to function normally. In addition, reconstructive surgery is performed to keep the patient’s facial appearance as good as possible, as well as to help patients to eat, drink and talk normally.
Reconstructive surgery is performed if the cancer has spread to organs around the parotid gland such as bone, muscles and facial nerves. This condition requires doctors to dispose of these tissues to prevent cancer from reappearing. Reconstructive surgery can utilize a skin graft method from other parts to improve the face, mouth and jaw area. In some people, dental implants are also required to replace parts of teeth and jaws removed after surgery.
Treatment of salivary gland can vary according to cancer progression in patients. In general, the combination of treatment given to patients according to the stage of cancer is as follows:
- Cancer stage I. In patients with stage I salivary gland cancer, the main treatment is surgery to remove cancer. Radiotherapy may be given if the patient has middle or malignant cystic adenoid carcinoma. Radiotherapy can also be given post-surgery to kill cancer that is not wasted through surgery.
- Cancer stage II. In patients with stage 2 salivary glands cancer, the main treatment given is more extensive surgery than in stage I cancer. In addition to removal of cancer, doctors can also remove the cancerous lymph nodes. Radiotherapy is used as an adjunctive therapy to kill the remnants of cancer cells.
- Cancer stage III. In stage III cancer patients, surgery extensively is a major step in cancer treatment. Surgery involves removal of the salivary glands, the lymph nodes, and the tissues surrounding the cancer. Radiotherapy and chemotherapy are given to kill the remnants of cancer cells left after surgery and prevent cancer cell metastasis.
- Cancer stage IV. In patients with stage IV cancer, the main treatment is surgery. But before surgery is done, the cancer in patients is minimized first through radiotherapy and chemotherapy. If doctors conclude that cancer cells can be removed by surgery, extensive surgery can be performed. After that, chemotherapy and radiotherapy can be given back to inhibit the growth of cancer that has spread to other organs.