Diagnosis is usually made by characteristic history and physical examination. Diagnosis can be confirmed by x-ray (80% of salivary gland calculi are visible on x-ray), by sialogram, or by ultrasound.

A salivary diverticulum (plural "diverticuli") is a small pouch or out-pocketing of the duct system of a major salivary gland. Such diverticuli typically cause pooling of saliva and recurrent sialadenitis, especially parotitis. A diverticulum may also cause a sialolith to form.

The condition can be diagnosed by sialography. Affected individuals may "milk" the salivary gland to encourage flow of saliva through the duct.

Some current treatment options are:

- Non-invasive:

- For small stones, hydration, moist heat therapy, NSAIDs (nonsteroidal anti-inflammatory drugs) occasionally, and having the patient take any food or beverage that is bitter and/or sour. Sucking on citrus fruits, such as a lemon or orange, may increase salivation and promote spontaneous expulsion of the stone.

- Some stones may be massaged out by a specialist.

- Shock wave therapy (Extracorporeal shock wave lithotripsy).

- Minimally invasive:

- Sialendoscopy

- Surgical:

- An ENT or oral/maxillofacial surgeon may cannulate the duct to remove the stone (sialectomy).

- A surgeon may make a small incision near the stone to remove it.

- In some cases when stones continually reoccur the offending salivary duct is removed.

- Supporting treatment:

- To prevent infection while the stone is lodged in the duct, antibiotics are sometimes used.

The histologic appearance is similar to mucoceles from other locations. The spilled mucin causes a granulation tissue to form, which usually contains foamy histiocytes. Ultrasound and magnetic resonance imaging may be useful to image the lesion. A small squamous cell carcinoma obstructing the Wharton duct may require clinical examination to be distinguished from a ranula.

Infections involving the salivary glands can be viral or bacterial (or rarely fungal).

- Mumps is the most common viral sialadenitis. It usually occurs in children, and there is preauricular pain (pain felt in front of the ear), swelling of the parotid, fever, chills, and headaches.

- Bacterial sialadentitis is usually caused by ascending organisms from the oral cavity. Risk factors include reduced salivary flow rate.

- Human immunodeficiency virus-associated salivary gland disease (HIV-SGD).

The lesion is usually present in children. Ranulas are the most common pathologic lesion associated with the sublingual glands.

Blockage of the main parotid duct, or one of its branches, is often a primary cause of acute parotitis, with further inflammation secondary to bacterial superinfection. The blockage may be from a salivary stone, a mucous plug, or, more rarely, by a tumor, usually benign. Salivary stones (also called sialolithiasis, or salivary duct calculus) are mainly made of calcium, but do not indicate any kind of calcium disorder. Stones may be diagnosed via X-ray (with a success rate of about 80%), a computed tomography (CT) scan or Medical ultrasonography. Stones may be removed by manipulation in the doctor's office, or, in the worst cases, by surgery. Lithotripsy, also known as "shock wave" treatment, is best known for its use breaking up kidney stones. Lithotripsy can now be used on salivary stones as well. Ultrasound waves break up the stones, and the fragments flush out of the salivary duct.

Salivary gland aplasia (also termed salivary gland agenesis) is the congenital absence of salivary glands. Usually the term relates to the absence of some or all of the major salivary glands.

It is a rare condition, and most known cases have been in association with syndromes of the ectodermal tissues, particularly the lacrimal apparatus. Example syndromes which have been reported with salivary gland aplasia include hereditary ectodermal dysplasia, mandibulofacial dysostosis and hemifacial microsomia.

The main significance of the condition is a lack of saliva, causing xerostomia (dry mouth), with accompanying susceptibility to dental caries (tooth decay), infections of the mouth, and upper respiratory tract infections (e.g., candidiasis, ascending sialadenitis, laryngitis and pharyngitis). Patients with salivary gland aplasia typically require regular application of topical fluoride to prevent tooth decay.

There are many diagnostic methods that can be used to determine the type of salivary gland tumour and if it is benign or malignant. Examples of diagnostic methods include:

Physical exam and history: An exam of the body to check general signs of health. The head, neck, mouth, and throat will be checked for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.

Endoscopy: A procedure to look at organs and tissues inside the body to check for abnormal areas. For salivary gland cancer, an endoscope is inserted into the mouth to look at the mouth, throat, and larynx. An endoscope is a thin, tube-like instrument with a light and a lens for viewing.

MRI

Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.

Fine needle aspiration (FNA) biopsy: The removal of tissue or fluid using a thin needle. An FNA is the most common type of biopsy used for salivary gland cancer, and has been shown to produce accurate results when differentiating between benign and malignant tumours.

Radiographs: An OPG (orthopantomogram) can be taken to rule out mandibular involvement. A chest radiograph may also be taken to rule out any secondary tumours.

Ultrasound: Ultrasound can be used to initially assess a tumour that is located superficially in either the submandibular or parotid gland. It can distinguish an intrinsic from an extrinsic neoplasm. Ultrasonic images of malignant tumours include ill defined margins.

A diagnosis of hyposalivation is based predominantly on the clinical signs and symptoms. There is little correlation between symptoms and objective tests of salivary flow, such as sialometry. This test is simple and noninvasive, and involves measurement of all the saliva a patient can produce during a certain time, achieved by dribbling into a container. Sialometery can yield measures of stimulated salivary flow or unstimulated salivary flow. Stimulated salivary flow rate is calculated using a stimulant such as 10% citric acid dropped onto the tongue, and collection of all the saliva that flows from one of the parotid papillae over five or ten minutes. Unstimulated whole saliva flow rate more closely correlates with symptoms of xerostomia than stimulated salivary flow rate. Sialography involves introduction of radio-opaque dye such as iodine into the duct of a salivary gland. It may show blockage of a duct due to a calculus. Salivary scintiscanning using technetium is rarely used. Other medical imaging that may be involved in the investigation include chest x-ray (to exclude sarcoidosis), ultrasonography and magnetic resonance imaging (to exclude Sjögren's syndrome or neoplasia). A minor salivary gland biopsy, usually taken from the lip, may be carried out if there is a suspicion of organic disease of the salivary glands. Blood tests and urinalysis may be involved to exclude a number of possible causes. To investigate xerophthalmia, the Schirmer test of lacrimal flow may be indicated. Slit-lamp examination may also be carried out.

Ectopic salivary gland tissue which is located in sites other than the normal location is variously described as aberrant, accessory, ectopic, heterotopic or salivary gland choristoma.

In one report, about 20% of individuals with mealtime syndrome had strictures upon sialography. For unknown reasons, strictures seem to be more common in females.

Strictures tend to be diagnosed based on difficulty with insertion and manipulation during sialendoscopy, or by sialography or ultrasound.

An "accessory salivary gland" is ectopic salivary gland tissue with a salivary gland duct system. The most common location of accessory salivary gland tissue is an extra major salivary gland in front of the parotid gland. It is typically about 3 cm or less in size, and drains into the parotid duct via a single tributary. Accessory parotid tissue is found in 21-56% of adults. Any disease process which affects the salivary glands, including cancer, may also occur within an accessory salivary gland tissue.

A salivary gland fistula (plural "fistulae") is a fistula (i.e. an abnormal, epithelial-lined tract) involving a salivary gland or duct.

Salivary gland fistulae are almost always related to the parotid gland or duct, although the submandibular gland is rarely the origin.

The fistula can communicate with the mouth (usually causing no symptoms), the paranasal sinuses (giving rhinorrhea) or the facial skin (causing saliva to drain onto the skin).

The usual cause is trauma, however salivary fistula can occur as a complication of surgery, or if the duct becomes obstructed with a calculus.

Most parotid fistulae heal by themselves within a few weeks.

These are also collectively known as chronic punctate parotitis or chronic autoimmune parotitis.

"Sjögren's syndrome:"

Chronic inflammation of the salivary glands may also be an autoimmune disease known as Sjögren's syndrome. The disease most commonly appears in people aged 40–60 years, but it may affect small children. In Sjögren syndrome, the prevalence of parotitis in women versus men is approximately 9:1. The involved parotid gland is enlarged and tender at times. The cause is unknown. The syndrome is often characterized by excessive dryness in the eyes, mouth, nose, vagina, and skin.

"Lymphoepithelial lesion of Godwin:"

Most frequently associated with a circumscribed tumor with the histologic features of Sjögren syndrome. This designation has also fallen out of favour.

From a pathology perspective, several tumors need to be considered in the differential diagnosis, including paraganglioma, ceruminous adenoma, metastatic adenocarcinoma, and meningioma.

Xerostomia is a very common symptom. A conservative estimate of prevalence is about 20% in the general population, with increased prevalences in females (up to 30%) and the elderly (up to 50%).

The condition is rare. It is more likely to occur in persons who regularly have raised pressure in the mouth, for example wind instrument players, and balloon and glass-blowers. Cases have also been reported with bicycle tyre inflation, whistling, nose blowing, cough and valsalva manoeuvre to clear the ears. It can be an iatrogenic effect of dental treatment, spirometry, and positive pressure ventilation. Apart from these factors, the condition mainly occurs in adolescents, often self-inflicted due to psychological issues.

The most common and helpful way to diagnose thyroiditis is first for a physician to palpate the thyroid gland during a physical examination. Laboratory tests allow doctors to evaluate the patient for elevated erythrocyte sedimentation rates, elevated thyroglobulin levels, and depressed radioactive iodine uptake (Mather, 2007). Blood tests also help to determine the kind of thyroiditis and to see how much thyroid stimulating hormone the pituitary gland is producing and what antibodies are present in the body. In some cases a biopsy may be needed to find out what is attacking the thyroid.

Pneumoparotitis is often misdiagnosed and incorrectly managed. The diagnosis is based mainly on the history. Crepitus may be elicited on palpation of the parotid swelling, and massaging the gland may give rise to frothy saliva or air bubbles from the parotid papilla. Further investigations are not typically required, however sialography, ultrasound and computed tomography may all show air in the parotid gland and duct.

Management is simply by avoidance of the activity causing raised intraoral pressure which is triggering this rare condition.

Generally, there is a good prognosis for low-grade tumors, and a poor prognosis for high-grade tumors.

The tumor must be removed with as complete a surgical excision as possible. In nearly all cases, the ossicular chain must be included if recurrences are to be avoided. Due to the anatomic site of involvement, facial nerve paralysis and/or paresthesias may be seen or develop; this is probably due to mass effect rather than nerve invasion. In a few cases, reconstructive surgery may be required. Since this is a benign tumor, no radiation is required. Patients experience an excellent long term outcome, although recurrences can be seen (up to 15%), especially if the ossicular chain is not removed. Although controversial, metastases are not seen in this tumor. There are reports of disease in the neck lymph nodes, but these patients have also had other diseases or multiple surgeries, such that it may represent iatrogenic disease.

Autoantibodies to the thyroid gland may be detected in various disease states. There are several anti-thyroid antibodies, including anti-thyroglobulin antibodies (TgAb), anti-microsomal/anti-thyroid peroxidase antibodies (TPOAb), and TSH receptor antibodies (TSHRAb).

- Elevated anti-thryoglobulin (TgAb) and anti-thyroid peroxidase antibodies (TPOAb) can be found in patients with Hashimoto's thyroiditis, the most common autoimmune type of hypothyroidism. TPOAb levels have also been found to be elevated in patients who present with subclinical hypothyroidism (where TSH is elevated, but free T4 is normal), and can help predict progression to overt hypothyroidism. The American Association Thyroid Association thus recommends measuring TPOAb levels when evaluating subclinical hypothyroidism or when trying to identify whether nodular thyroid disease is due to autoimmune thyroid disease.

- When the etiology of hyperthyroidism is not clear after initial clinical and biochemical evaluation, measurement of TSH receptor antibodies (TSHRAb) can help make the diagnosis. In Grave's disease, TSHRAb levels are elevated as they are responsible for activating the TSH receptor and causing increased thyroid hormone production.

Treatment may include the following:

- Surgery with or without radiation

- Radiotherapy

Fast neutron therapy has been used successfully to treat salivary gland tumors, and has shown to be significantly more effective than photons in studies treating unresectable salivary gland tumors.

- Chemotherapy