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.

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

The diagnosis of salivary gland tumors utilize both tissue sampling and radiographic studies. Tissue sampling procedures include fine needle aspiration (FNA) and core needle biopsy (bigger needle comparing to FNA). Both of these procedures can be done in an outpatient setting. Diagnostic imaging techniques for salivary gland tumors include ultrasound, computer tomography (CT) and magnetic resonance imaging (MRI).

Fine needle aspiration biopsy (FNA), operated in experienced hands, can determine whether the tumor is malignant in nature with sensitivity around 90%. FNA can also distinguish primary salivary tumor from metastatic disease.

Core needle biopsy can also be done in outpatient setting. It is more invasive but is more accurate compared to FNA with diagnostic accuracy greater than 97%. Furthermore, core needle biopsy allows more accurate histological typing of the tumor.

In terms of imaging studies, ultrasound can determine and characterize superficial parotid tumors. Certain types of salivary gland tumors have certain sonographic characteristics on ultrasound. Ultrasound is also frequently used to guide FNA or core needle biopsy.

CT allows direct, bilateral visualization of the salivary gland tumor and provides information about overall dimension and tissue invasion. CT is excellent for demonstrating bony invasion. MRI provides superior soft tissue delineation such as perineural invasion when compared to CT only.

It is important to exclude a tumor which is directly extending into the ear canal from the parotid salivary gland, especially when dealing with an adenoid cystic or mucoepidermoid carcinoma. This can be eliminated by clinical or imaging studies. Otherwise, the histologic differential diagnosis includes a ceruminous adenoma (a benign ceruminous gland tumor) or a neuroendocrine adenoma of the middle ear (middle ear adenoma).

Ultrasound-guided FNAC should be performed for verification of SCTC.

Immunohistochemistry is performed as additional test. The strong positive expression of cytokeratin 19 was showed in primary SCTC, and negative in metastatic SCTC.

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

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

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

EMCas are diagnosed by examination of tissue, e.g. a biopsy.

Its appearance is very similar to adenomyoepithelioma of the breast, which may be the same tumour at a different anatomical site.

The histologic differential diagnosis includes adenoid cystic carcinoma and pleomorphic adenoma.

Most of these tumors are treated with surgical removal. It is non recurrent.

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

Patients treated with complete surgical excision can expect an excellent long term outcome without any problems. Recurrences may be seen in tumors which are incompletely excised.

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.

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).

While there is a wide age range at clinical presentation (12–85 years), most patients come to clinical attention at 55 years (mean). There is no gender difference.

Patients with thyroid oncocytomas present with a thyroid nodule, usually with normal thyroid function. If the tumor is big or invasive, there may be other symptoms such as difficulty swallowing or talking.

Thyroid oncocytomas can be benign (adenomas) or malignant (carcinomas). Grossly, oncocytic adenomas are encapsulated, solid nodules with a characteristic brown cut surface. The gross appearance of a minimally invasive oncocytic carcinoma is indistinguishable to that of an adenoma, while widely invasive oncocytic carcinomas are obviously invasive macroscopically and display pervasive vascular invasion with multifocal involvement of the thyroid gland. There are no reliable cytologic features which distinguish oncocytic adenomas from carcinomas and the only criterion for a diagnosis of malignancy is the identification of transcapsular or vascular invasion.

PLGAs consist of a monomorphous cell population that has a varied histologic morphology.

Microscopically, its histology can be confused with an adenoid cystic carcinoma and a pleomorphic adenoma.

Wide, radical, complete surgical excision is the treatment of choice, with free surgical margins to achieve the best outcome and lowest chance of recurrence. Radiation is only used for palliation. In general, there is a good prognosis, although approximately 50% of patients die from disease within 3–10 years of presentation.

Overall, the mainstay of the treatment for salivary gland tumor is surgical resection. Needle biopsy is highly recommended prior to surgery to confirm the diagnosis. More detailed surgical technique and the support for additional adjuvant radiotherapy depends on whether the tumor is malignant or benign.

Surgical treatment of parotid gland tumors is sometimes difficult, partly because of the anatomical relationship of the facial nerve and the parotid lodge, but also through the increased potential for postoperative relapse. Thus, detection of early stages of a tumor of the parotid gland is extremely important in terms of prognosis after surgery.

Generally, benign tumors of the parotid gland are treated with superficial(Patey's operation) or total parotidectomy with the latter being the more commonly practiced due to high incidence of recurrence. The facial nerve should be preserved whenever possible. The benign tumors of the submandibular gland is treated by simple excision with preservation of mandibular branch of the trigeminal nerve, the hypoglossal nerve, and the lingual nerve. Other benign tumors of minor salivary glands are treated similarly.

Malignant salivary tumors usually require wide local resection of the primary tumor. However, if complete resection cannot be achieved, adjuvant radiotherapy should be added to improve local control. This surgical treatment has many sequellae such as cranial nerve damage, Frey's syndrome, cosmetic problems, etc.

Usually about 44% of the patients have a complete histologic removal of the tumor and this refers to the most significant survival rate.

Myoepitheliomas are diagnosed from an examination of the tissue by a pathologist.

This type of carcinoma is commonly managed by local resection, cryotherapy, topical chemotherapy, and radiotherapy. Multimodal therapy has been shown to improve both visual prognosis and survival.

Mohs micrographic surgery has become the treatment of choice for this form of cancer. When used as the primary treatment modality for sebaceous carcinoma of the eyelid, Mohs surgery is associated with significantly lower local and distant recurrence rates.

Carcinoma ex pleomorphic adenoma is diagnosed by examining it under the microscope with consideration of the individual history.

In approximately 75% of cases ca ex PAs arise in a pleomorphic adenoma that is apparent when the tumour is excised. In the other approximately 25% of cases the individual had a pleomorphic adenoma excised previously and the diagnosis is made based on (1) the presence of a carcinoma, and (2) the history of a pleomorphic adenoma at that location.

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.