Responsible for the secretion of saliva, there are two types of salivary glands: the main salivary glands and the accessory salivary glands. They can be the site of bacterial or viral infection, lithiasis, benign tumors or, more rarely, malignant tumors. Cancers of the salivary glands are indeed quite rare cancers.

There are two types of salivary glands:

• accessory glands, located in the lining of the oral cavity and tongue. They are small in size and simple in structure;
• the main salivary glands, located outside the wall of the oral cavity. Larger, they are individualized organs with a more complex structure. They are formed of secretory units and others, excretory.

Among the main salivary glands we can distinguish:

• the parotid glands located in front of the ear, in the cheek. There are therefore two. Their canal opens onto the internal face of the cheek, at the level of the molars;
• the submandibular glands are below the jawbone. Their canal opens out near the frenulum of the tongue;
• the sublingual glands are located under the tongue. Their canal also opens near the frenulum of the tongue.

The salivary glands produce saliva. As a reminder, saliva is a mixture of water, electrolytes, desquamated cells and serous secretions, including enzymes. Saliva fulfills different functions: it maintains the hydration of the mouth, participates in the first stages of digestion thanks to the enzymes, ensures an antibacterial role thanks to the antibodies.

The main salivary glands secrete saliva in response to stimuli while the accessory salivary glands secrete continuously.

Salivary gland lithiasis (sialolithiasis)

Stones can form in the salivary ducts of one of the submandibular glands most often. They block the flow of saliva, causing painless swelling of the salivary gland. It is a benign pathology.

Bacterial infection

When saliva stagnates in the gland due to an obstacle to its evacuation (lithiasis, narrowing of the duct), it can become infected. This is called sialitis or glandular infection, parotitis when the parotid gland is affected and submandibulitis when it comes to the submandibular gland. The gland is then swollen, tense, painful. Pus may appear, as well as a fever.

Juvenile recurrent parotitis

A particular form of parotitis affecting children and adolescents, they are repeated bacterial infections of one or both parotid glands. The risk being, in the long term, the destruction of the glandular parenchyma (cells constituting the secretory tissue).

Viral infections

Many viruses can reach the salivary glands, especially the parotid glands. The best known is that of mumps, a paramyxovirus known as the “mumps” virus which is easily transmitted through saliva. Mumps is manifested by painful swelling of one or both parotid glands, ear pain, throat pain, fever, and severe fatigue. Usually mild in children, the disease can lead to complications in adolescents, adults and pregnant women: meningitis, hearing loss, pancreatitis, testicular damage that can lead to infertility. The MMR vaccine is the best way to prevent mumps.

Pseudo-allergic sialitis

Less known and often leading to therapeutic wandering, pseudo-allergic sialitis manifests itself by sometimes painful swelling of one or more salivary glands during meals or gustatory or olfactory stimulation, accompanied by significant itching. The causes of this disease remain unknown today.

Benign tumors

Most salivary gland tumors are benign. They most often concern the parotid glands. They appear as an isolated, firm, mobile and painless nodule that grows slowly.

The most common tumor is pleomorphic adenoma. It can progress to a malignant tumor, but only 15 to 20 years after it appears. Other benign tumors exist: monomorphic adenoma, oncocytoma and cystadenolymphoma (Warthin’s tumor).

Malignant tumors – cancers of the salivary glands

Malignant salivary gland tumors manifest as a hard, nodular mass, usually adherent to adjacent tissue, with an ill-defined outline. These are rare tumors (incidence less than 1 / 100), representing less than 000% of tumors of the head and neck. Metastatic evolution is observed in approximately 5% of cases.

Different cancerous tumors of the salivary glands exist. The latest classification of the World Health Organization (2005) thus recognizes 24 different types of malignant epithelial tumors and 12 types of benign epithelial tumors. Here are the main ones:

• mucoepidermoid carcinoma is the most common cancer of the salivary glands. It generally affects the parotid gland, more rarely the submandibular gland or the minor salivary gland of the palate;
• Adenoid cystic carcinoma is the second most common type of tumor. It usually affects the accessory salivary glands and can spread to the nerves in the face. Depending on the nature of the cancer cells, a distinction is made between cribriform adenoid cystic carcinoma (the most common), solid adenoid cystic carcinoma and tuberous adenoid cystic carcinoma;
• salivary duct carcinoma usually affects the parotid gland. Rapidly growing and very aggressive, it spreads easily to the lymph nodes;
• acinar cell carcinoma usually affects the parotid gland, sometimes both;
• primary lymphomas of the salivary glands are rare.

Other types of salivary gland tumors exist, but they are much rarer.

Bacterial infection

Antibiotic treatment is prescribed. An ultrasound check is performed to ensure complete healing of the gland.

Viral infection

The ears usually heal spontaneously within ten days. Since the infection is viral, no antibiotics are necessary. Only fever and pain can be treated with antipyretics or analgesics.

A viral infection of the salivary glands can become secondary to a bacterial infection. It will then require antibiotic treatment.

Salivary lithiasis

Salivary stones usually go away with the help of regular massages of the salivary gland. If they persist, sialendoscopy (endoscopy of the ducts and salivary glands) may be performed. Another technique, called extracorporeal lithotripsy, consists of fragmenting the stones with extracorporeal shock waves.

Sialectomy (a surgical act consisting in opening the salivary duct to extract the calculus) has been carried out less and less since the development of these two techniques.

Pseudo-allergic sialitis

The management begins with a treatment of attack of 2 weeks combining bi-antibiotic therapy, corticosteroid therapy, antispasmodics, antiallergics and benzodiazepine. A long-term treatment based on weak corticosteroids and antiallergic is then prescribed.

Benign tumors

The treatment of benign tumors is surgical excision. It must be complete and with a safety margin to limit the risk of recurrence.

Cancerous tumors

The treatment of malignant salivary gland tumors is surgery with a large margin of safety, sometimes followed by radiotherapy for certain cancers. Depending on the spread, lymph nodes in the neck are sometimes removed. Chemotherapy is not indicated, except in rare cases.

The prognosis is variable depending on the nature of the cancer, its spread, its stage of development and the success of the surgery.

It is generally the presence of a mass that leads the patient to consult his general practitioner or his ENT doctor. Faced with a lump in a salivary gland, various examinations may be prescribed:

• a clinical examination to evaluate the measurements of the lesion, the local and regional extension with the search for cervical lymphadenopathy (lymph nodes);
• the x-ray shows the stones;
• sialography involves injecting a contrast product into the salivary gland to make it opaque. it is mainly used for the exploration of infectious diseases of the salivary glands;
• an anatomo-pathological examination of the sample in the event of tumors; to confirm the diagnosis of malignant neoplasia, specify its histological type and if possible its grade;
• an MRI, or failing that an ultrasound or a CT scan;
• a CT scan of the neck and thorax to look for possible metastatic involvement.