Pain is the most common symptom, followed by either sensorineural or conductive hearing loss, tinnitus or drainage (discharge). A mass lesion may be present, but it is often slow growing.

Due to the diverse nature of salivary gland tumours, many different terms and classification systems have been used. Perhaps the most widely used currently is that system proposed by the World Health Organization in 2004, which classifies salivary neoplasms as primary or secondary, benign or malignant, and also by tissue of origin. This system defines five broad categories of salivary gland neoplasms:

Benign epithelial tumors

- Pleomorphic adenoma

- Warthin's tumor

- Myoepithelioma

- Basal cell adenoma

- Oncocytoma

- Canalicular adenoma

- Lymphadenoma

- "Sebaceous lymphadenoma"

- "Nonsebaceous lymphadenoma"

- Ductal papilloma

- "Inverted ductal papilloma"

- "Intraductal papilloma"

- "Sialadenoma papilliferum"

- Cystadenoma

- Malignant epithelial tumors

- Acinic cell carcinoma

- Mucoepidermoid carcinoma

- Adenoid cystic carcinoma

- Polymorphous low-grade adenocarcinoma

- Epithelial-myoepithelial carcinoma

- Clear cell carcinoma, not otherwise specified

- Basal cell adenocarcinoma

- Sebaceous carcinoma

- Sebaceous lymphadenocarcinoma

- Cystadenocarcinoma

- Low-grade cribriform cystadenocarcinoma

- Mucinous adenocarcinoma

- Oncocytic carcinoma

- Salivary duct carcinoma

- Salivary duct carcinoma, not otherwise specified

- Adenocarcinoma, not otherwise specified

- Myoepithelial carcinoma

- Carcinoma ex pleomorphic adenoma

- Mammary analogue secretory carcinoma

- Carcinosarcoma

- Metastasizing pleomorphic adenoma

- Squamous cell carcinoma

- Large cell carcinoma

- Lymphoepithelial carcinoma

- Sialoblastoma

- Soft tissue tumors

- Hemangioma

- Hematolymphoid tumors

- Hodgkin lymphoma

- Diffuse large B-cell lymphoma

- Extranodal marginal zone B cell lymphoma

- Secondary tumors (i.e. a tumor which has metastasized to the salivary gland from a distant location)

Others, not included in the WHO classification above, include:

- Intraosseous (central) salivary gland tumors

- Hybrid tumors (i.e. a tumor displaying combined forms of histologic tumor types)

- Hybrid carcinoma

- Others

- Others

- Keratocystoma

- Sialolipoma

This tumor only affects the outer 1/3 to 1/2 of the external auditory canal as a primary site. If this area is not involved, the diagnosis should be questioned. The most common tumor type is ceruminous adenoid cystic carcinoma and ceruminous adenocarcinoma, NOS.

Salivary gland tumours usually present as a lump or swelling in the affected gland which may or may not have been present for a long time. The lump may be accompanied by symptoms of duct blockage (e.g. xerostomia). Usually, in their early stages it is not possible to distinguish a benign tumour from a malignant one. One of the key differentiating symptoms of a malignant growth is nerve involvement. For example signs of facial nerve damage (e.g facial palsy) are associated with malignant parotid tumours. Facial pain, and paraesthesia are also very often associated with a malignant tumours. Other red flag symptoms which may suggest malignancy and warrant further investigation are fixation of the lump to the overlying skin, ulceration and induration of the mucosa.

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.

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.

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.

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.

Malignant transformation to squamous cell carcinoma may occur, but is unusual.

Swelling is the most common presenting complaint; however, OKCs may be asymptomatic and found incidentally on dental X-rays.

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.

A common symptom of laryngeal papillomatosis is a perceptual change in voice quality. More specifically, hoarseness is observed. As a consequence of the narrowing of the laryngeal or tracheal parts of the airway, shortness of breath, chronic cough and stridor (i.e. noisy breathing which can sound like a whistle or a snore), can be present. As the disease progresses, occurrence of secondary symptoms such as dysphagia, pneumonia, acute respiratory distress syndrome, failure to thrive, and recurrent upper respiratory infections can be diagnosed. In children, symptoms are usually more severe and often mistaken for manifestations of other diseases such as asthma, croup or bronchitis. Therefore, diagnosis is usually delayed.

It is important to correctly identify, as it can be confused with atypical ductal hyperplasia, cribriform ductal carcinoma in situ (DCIS), and adenoid cystic carcinoma.

Basophilic, bland cells similar to acinar cells. Growth pattern: solid - acinar cells, microcytic - small systic spaces mucinous or eosinophilic, papillary-cystic - large cystic lined by epithelium, follicular - similar to thyroid tissue.

These tumors which resemble serous acinar cells vary in their behavior from locally aggressive to blatantly malignant.

It can also appear in the breast. The pancreatic form of acinic cell carcinoma is a rare subtype of exocrine pancreatic cancer. Exocrine pancreatic cancers are the most common form of pancreatic cancer when compared to endocrine pancreatic cancer.

Acinic cell carcinomas arise most frequently in the parotid gland. Other sites of primary tumors have included the submandibular gland and other major and minor salivary glands. There have been rare cases of primary tumors involving the parapharyngeal space and the sublingual gland.

Cystic nephromas are often asymptomatic. They are typically discovered on medical imaging incidentally (i.e. an incidentaloma).

Epithelial-myoepithelial carcinoma of the lung (EMECL) is a very rare histologic form of malignant epithelial neoplasm ("carcinoma") arising from lung tissue.

The symptoms may be similar to those classically associated with renal cell carcinoma, and may include polycythemia, abdominal pain, hematuria and a palpable mass. Mean age at onset is around 40 years with a range of 5 to 83 years and the mean size of the tumour is 5.5 cm with a range 0.3 to 15 cm (1). Polycythemia is more frequent in MA than in any other type of renal tumour. Of further relevance is that this tumour is more commonly calcified than any other kidney neoplasm. Surgery is curative and no other treatment is recommended. There is so far no evidence of metastases or local recurrence.

Metanephric adenoma (MA)is a rare, benign tumour of the kidney, that can have a microscopic appearance similar to a nephroblastoma (Wilms tumours), or a papillary renal cell carcinoma.

It should not be confused with the pathologically unrelated, yet similar sounding, "mesonephric adenoma".

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.

Collagenous spherulosis, also mucinous spherulosis and simply spherulosis, is a benign finding in breast pathology. It is almost always an incidental finding, though it is occasionally associated with calcifications, which may lead to a biopsy.

Most patients present clinically with progressive, one sided hearing loss, much more often of the sensorineural rather than conductive type. Patients may also experience tinnitus, vertigo, and loss of vestibular function (ataxia). Symptoms are usually present for a long time, which supports the slow growth of these tumors. Patients may also present with other symptoms related to von Hippel-Lindau syndrome in other anatomic sites, which will result in imaging evaluation of the head.

Cystitis glandularis is a term describing a metaplasial transformation of mucosal cells lining the urinary bladder. The main importance is in histopathology, distinguishing the metaplastic change from urothelial cell carcinoma. It is a very common finding in bladder biopsies and cystectomies, and most often found in the trigone area. Cystitis glandularis lesions are usually present as small microscopic foci; however, occasionally it can form raised intramucosal or polypoid lesions. The cystitis glandularis lesions are within the submucosa.

There are two main types of cystitis glandularis, non-mucinous and mucinous (intestinal). The difference is in the cellular production of mucin, a normal feature of colonic and intestinal epithelial cells but not of urothelial cells. Another distinction is made between focal areas and diffuse involvement of the bladder. Whereas focal areas are more common, diffuse involvement is seen in chronically irritated bladders, such as in paraplegics or those with bladder stones or indwelling catheters. Individuals with diffuse intestinal-type cystitis glandularis are at increased risk for developing bladder cancer.

The early lesions are usually asymptomatic. The patients presenting with an advanced stage of the disease comprises around 66-77% of the cases.

The most important signs include a lump in the neck when palpated and weight loss.

People may also present with fatigue as a symptom.

The primary tumor does not have readily discernible signs or symptoms as they grow within the tonsillar capsule. It is difficult to notice anything suspicious on examination of the tonsil other than slight enlargement or the development of firmness around the area.

The carcinoma may occur in one or more sites deep within the tonsillar crypts. It may be accompanied by the enlargement of the tonsil. The affected tonsil grows into the oropharyngeal space making it noticeable by the patient in the form of a neck mass mostly in the jugulodiagastric region.

As the tonsils consist of a rich network of lymphatics, the carcinoma may metastasise to the neck lymph nodes which many are cystic.

Extension of tumor to skull or mediastinum can occur.

The additional symptoms include a painful throat, dysphagia, otalgia (due to cranial nerve involvement), foreign body sensation, bleeding, fixation of tongue (infiltration of deep muscles) and trismus (if the pterygoid muscle is involved in the parapharyngeal space).

On the other hand, the tumor may also present as a deep red or white fungating wound growing outwards, breaking the skin surface with a central ulceration. This wound-like ulcer fails to heal (non-healing) leading to bleeding and throat pain and other associated symptoms.

During biopsy, the lesion may show three signs: Gritty texture, Firmness and cystification owing to keratinization, fribrosis and necrosis respectively.

Cervical lymphydenopathy may be present.

Laryngeal papillomatosis, also known as recurrent respiratory papillomatosis, is a rare medical condition that leads to audible changes in voice quality and narrowing of the airway. It is caused by type 6 and 11 human papillomavirus (HPV) infections of the throat, in which benign tumors or papillomas form on the larynx or other areas of the respiratory tract. Laryngeal papillomatosis is initially diagnosed through indirect laryngoscopy upon observation of growths on the larynx and can be confirmed through a biopsy. Treatment for laryngeal papillomatosis aims to remove the papillomas and limit their recurrence. Due to the recurrent nature of the virus, repeated treatments usually are needed. Laryngeal papillomatosis is primarily treated surgically, though supplemental nonsurgical and/or medical treatments may be considered in some cases. The evolution of laryngeal papillomatosis is highly variable. Though total recovery may be observed, it is often persistent despite treatment. The number of new cases of laryngeal papillomatosis cases is at approximately 4.3 cases per 100 000 children and 1.8 cases per 100 000 adults annually.