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

Occurs in adults, with peak incidence from 20–40 years of age. A causal link with cytomegalovirus (CMV) has been strongly implicated in a 2011 research.

They generally have a good prognosis. In one larger study, the 5-year and 10-year survival were over 90% and 80% respectively.

This is a very rare neoplasm accounting for approximately 0.0003% of all tumors and about 2.5% of all external ear neoplasms. There is a wide age range at initial presentation, although the mean age is about 50 years of age. Females are affected slightly more often (1.5:1).

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

Little is known about the total incidence of salivary gland tumours as most benign tumours go unrecorded in national cancer registries. The majority of salivary tumours are benign (65-70%). Within the parotid gland 75 - 80% of tumours are benign. Around 50% of the tumours found in the submandibular glands are benign. Sublingual gland tumours are very rare but if present, they are most likely to be malignant.

In the United States, salivary gland cancers are uncommon with an incidence rate of 1.7 in 100000 between 2009 and 2013.

Ductal carcinoma is a type of tumor that primarily presents in the ducts of a gland.

Types include:

- Mammary

- Ductal carcinoma in situ

- Invasive ductal carcinoma

- Pancreatic ductal carcinoma

Its cause is unknown, but there is a strong association with cigarette smoking. Smokers are at 8 times greater risk of developing Warthin's tumor than the general population.

Epithelial-myoepithelial carcinoma, abbreviated EMCa, is a rare malignant tumour that typically arises in a salivary gland and consists of both an epithelial and myoepithelial component. They are predominantly found in the parotid gland

and represent approximately 1% of salivary gland tumours.

Salivary duct carcinoma, abbreviated SDC, is a rare type of aggressive cancer that arises from the salivary glands. It is predominantly seen in men and, generally, has a poor prognosis. Other high grade carcinomas can mimic SDC. About 40-60% of SDC arise in pleomorphic adenomas. Most, if not all, SDCs express androgen receptor by immunohistochemistry. Therapeutically relevant genetic alterations include "ERBB2/Her2" amplification, "PIK3CA" and/or "HRAS" mutations.

Benign myoepithelioma are treated with simple excision. They are less prone to recurrence than pleomorphic adenoma.

Ceruminous adenocarcinoma is a malignant neoplasm derived from ceruminous glands of the external auditory canal. This tumor is rare, with several names used in the past. Synonyms have included cylindroma, ceruminoma, ceruminous adenocarcinoma, not otherwise specified (NOS), ceruminous adenoid cystic carcinoma (ACC), and ceruminous mucoepidermoid carcinoma.

The gland most likely affected is the parotid gland. In fact, it is the only tumor virtually restricted to the parotid gland. Though much less likely to occur than pleomorphic adenoma, Warthin's tumor is the second most common benign parotid tumor.

Thymic carcinoma is a rare type of thymus gland cancer. It usually spreads, has a high risk of recurrence, and has a poor survival rate. Thymic carcinoma is divided into subtypes, depending on the types of cells in which the cancer began. Also called type C thymoma.

PLGAs are treated with wide local surgical excision and long-term follow-up.

There is a recurrence rate of 14% (Peterson, contemporary of oral and maxillofacial surgery).

Polymorphous low-grade adenocarcinoma, often abbreviated PLGA, is a rare, asymptomatic, slow-growing malignant salivary gland tumor. It is most commonly found in the palate.

The name of the tumor derives from the fact that:

- It has a varied microscopic architectural appearance, i.e. it is "polymorphous".

- It is non-aggressive when compared to other oral cavity tumors, i.e. it is a "low-grade" tumor.

- It forms glands, i.e. it is an "adenocarcinoma".

It affects the minor salivary glands in the area between the hard and the soft palate. Male to female ratio is 3:1, and the average age is 56 years.

Acinic cell carcinoma appears in all age groups, but presents at a younger median age (approx. 52 years) than most other salivary gland cancers. Occurrences in children are quite common.

Adenoid cystic carcinoma (sometimes referred to as adenocyst, malignant cylindroma, adenocystic, adenoidcystic, ACC or AdCC.) is a rare type of cancer that can exist in many different body sites. This tumor most often occurs in the salivary glands, but it can also be found in many anatomic sites, including the breast, lacrimal gland, lung, brain, bartholin gland, trachea, and the paranasal sinuses.

It is the third most common malignant salivary gland tumor overall (after mucoepidermoid carcinoma and polymorphous low grade adenocarcinoma). It represents 28% of malignant submandibular gland tumors, making it the single most common malignant salivary gland tumor in this region. Patients may survive for years with metastases because this tumor is generally well-differentiated and slow growing. In a 1999 study of a cohort of 160 ACC patients, disease specific survival was 89% at 5 years but only 40% at 15 years, reflecting deaths from late-occurring metastatic disease.

Sebaceous lymphadenoma is a tissue diagnosis, e.g. salivary gland biopsy.

It may be confused with a number of benign and malignant neoplasms, including Warthin tumour, mucoepidermoid carcinoma and sebaceous lymphadenocarcinoma.

Primary treatment for this cancer, regardless of body site, is surgical removal with clean margins. This surgery can prove challenging in the head and neck region due to this tumour's tendency to spread along nerve tracts. Adjuvant or palliative radiotherapy is commonly given following surgery. For advanced major and minor salivary gland tumors that are inoperable, recurrent, or exhibit gross residual disease after surgery, fast neutron therapy is widely regarded as the most effective form of treatment.

Chemotherapy is used for metastatic disease. Chemotherapy is considered on a case by case basis, as there is limited trial data on the positive effects of chemotherapy. Clinical studies are ongoing, however.

Pleomorphic adenoma is a common benign salivary gland neoplasm characterised by neoplastic proliferation of parenchymatous glandular cells along with myoepithelial components, having a malignant potentiality. It is the most common type of salivary gland tumor and the most common tumor of the parotid gland. It derives its name from the architectural Pleomorphism (variable appearance) seen by light microscopy. It is also known as "Mixed tumor, salivary gland type", which describes its pleomorphic appearance as opposed to its dual origin from epithelial and myoepithelial elements.

Hidradenocarcinoma (also known as malignant hidradenoma, malignant acrospiroma, clear cell eccrine carcinoma, or primary mucoepidermoid cutaneous carcinoma) is a malignant adnexal tumor of the sweat gland. It is the malignant variant of the benign hidradenoma. It may develop de novo or in association with an existent hidradenoma.

This type of tumor typically develops in older individuals (after age 40).

The typical presentation is a rapidly growing mass with associated pain. This may be seen in association with neck lymph node swelling (cervical lymphadenopathy), due to metastases, and facial nerve paralysis.

The treatment is simple excision and exclusion of a malignant neoplasm.

The exact cause of the condition is unknown. There is most evidence to support vascular infarction and ischemic necrosis of salivary gland lobules as a mechanism for the condition. Experimentally, local anaesthetic injections and tying of the arteries is reported to trigger the development of tissue changes similar to NS in lab rats. Factors which are thought to cause this ischemia are listed below, however sometimes there is no evident predisposing factor or initiating event.

- Trauma e.g. during intubation, or surgical procedures

- Local anesthetic injection

- Smoking

- Alcohol

- Diabetes mellitus

- Vascular disease, (e.g. arteriosclerosis)

- Pressure from a dental prosthesis

- Allergy

- Bulimia

- Infection

- Ionizing radiation