What are the other Names for this Condition? (Also known as/Synonyms)

• Clear Cell Adenocarcinoma of Salivary Gland
• Hyalinizing Clear Cell Carcinoma of Salivary Gland
• Salivary Gland Clear Cell Carcinoma, Not Otherwise Specified

What is Clear Cell Carcinoma (NOS) of Salivary Gland? (Definition/Background Information)

• Clear Cell Carcinoma (NOS) of Salivary Gland is a malignant epithelial tumor, uniformly composed of clear cells, affecting mostly the minor salivary glands. It is observed in a wide age category of adults
• Since, features of this clear cell tumor is observed in most salivary gland tumors, the diagnosis may be based on exclusion (eliminating other similar tumors) before definitively diagnosing Salivary Gland Clear Cell Carcinoma, NOS
• The cause of formation of this salivary gland malignancy is generally unknown, but may be due to genetic factors. No definitive risk factors are observed, though salivary gland cancers are known to be influenced by factors such as exposure to radiation sources and occupational exposure to hazardous chemicals/products
• The signs and symptoms of Clear Cell Carcinoma (NOS) of Salivary Gland may include a tumor growth forming a lump, associated with pain in some cases, facial paralysis, and eating/chewing difficulties. Tumors in the oral cavity are known to ulcerate and bleed
• The treatment for Clear Cell Carcinoma (NOS) of Salivary Gland involves a combination of surgery, chemotherapy, and radiation therapy, in most cases. With prompt diagnosis and adequate treatment, the prognosis is generally excellent

Who gets Clear Cell Carcinoma (NOS) of Salivary Gland? (Age and Sex Distribution)

• Most cases of Clear Cell Carcinoma (NOS) of Salivary Gland has been recorded in adults in the 40-70 year’s age group. The tumor is very rarely observed in children
• Both male and female genders are affected, and no ethnic or racial preference has been observed

What are the Risk Factors for Clear Cell Carcinoma (NOS) of Salivary Gland? (Predisposing Factors)

No risks are evident for Clear Cell Carcinoma (NOS) of Salivary Gland. Nevertheless, the following risk factors are generally noted for salivary gland cancers:

• Exposure to ionizing radiation (which may be from natural or artificial sources)
• Occupations involving woodwork, plumbing, and mining (asbestos)
• Working in manufacturing industry related to certain materials, such as rubber products

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Clear Cell Carcinoma (NOS) of Salivary Gland? (Etiology)

The exact cause of Clear Cell Carcinoma (NOS) of Salivary Gland formation is unknown. It is suggested that genetic factors may have a role in their formation.

• In general, it is known that cancers form when normal, healthy cells begin transforming into abnormal cells - these cancer cells grow and divide uncontrollably (and lose their ability to die), resulting in the formation of a mass or a tumor
• The transformation of normally healthy cells into cancerous cells may be the result of genetic mutations. Mutations allow the cancer cells to grow and multiply uncontrollably to form new cancer cells
• These tumors can invade nearby tissues and adjoining body organs, and even metastasize and spread to other regions of the body

What are the Signs and Symptoms of Clear Cell Carcinoma (NOS) of Salivary Gland?

Clear Cell Carcinoma (NOS) of Salivary Gland signs and symptoms may include the following:

• A presence of single, poorly-defined tumors with infiltrative borders
• Infiltration may take place into the surrounding tissue, mucosa, bone, and nerves
• Most clear cell tumors are slow-growing and present no pain; some tumors are known to be present for many years (up to 15 years recorded)
• Presence of visible swelling inside the mouth, that is slowly increasing in size
• The size of the tumor is generally not more than 3 cm
• Tumors in the oral mucosa are known to ulcerate, bleed, and present pain
• Pain while eating/chewing
• Neurological signs and symptoms, such as facial muscle weakness and pain, due to facial nerve involvement may be noted
• Persistent facial pain at the site of swelling of the tumor; this requires an immediate checkup by a healthcare provider

Location of the malignant tumor:

• Major salivary glands: Only some cases have been reported in these glands
• Minor salivary glands: Many cases are observed inside the mouth, affecting the minor glands. The tumor sites include the palate (most common site), inner cheek lining (buccal mucosa), lip, tongue, floor of the mouth, tonsils, and behind the jaws (retromolar pad)

How is Clear Cell Carcinoma (NOS) of Salivary Gland Diagnosed?

A diagnosis of Clear Cell Carcinoma (NOS) of Salivary Gland is made using the following tools:

• Complete evaluation of family (medical) history, along with a thorough physical examination
• Plain X-ray of the head and neck
• Ultrasound scan of the affected salivary gland
• CT or CAT scan with contrast of the head and neck may show a tumor mass. This radiological procedure creates detailed 3-dimensional images of structures inside the body
• MRI scans of head and neck: Magnetic resonance imaging (MRI) uses a magnetic field to create high-quality pictures of certain parts of the body, such as tissues, muscles, nerves, and bones. These high-quality pictures may reveal the presence of the tumor

Although the above modalities can be used to make an initial diagnosis, a tissue biopsy of the tumor is necessary to make a definitive diagnosis to begin treatment. The tissue for diagnosis can be procured in multiple different ways which include: 

• Fine needle aspiration (FNA) biopsy of the tumor: A FNA biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a FNA biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred
• Salivary gland core biopsy of the tumor
• Salivary gland open biopsy of the tumor

Tissue biopsy of the tumor:

• A tissue biopsy of the nodule is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
• Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies to assist in the diagnosis

A differential diagnosis may be necessary to eliminate other salivary gland tumors presenting similar signs and symptoms prior to a definite diagnosis of clear cell tumors.

Note: Some epithelial-myoepithelial tumors have been diagnostically confused as clear cell carcinomas.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Clear Cell Carcinoma (NOS) of Salivary Gland?

Complications of Clear Cell Carcinoma (NOS) of Salivary Gland may include:

• Cosmetic concerns (facial disfigurement) and severe emotional stress
• Ulceration and bleeding from the tumor
• Large-sized tumors may compress adjoining tissues and structures resulting in additional complications
• Breathing or swallowing difficulties (if tumor mass obstructs the food-pipe or wind-pipe)
• Recurrence of the tumor after surgery
• Bones may be affected and undergo demineralization
• Tumor metastasis to local and distant sites can take place, but is very uncommon. When reported, the neck (cervical) lymph nodes have been involved, while other distant sites include the lung
• Surgical complications: Surgery to remove the tumor mass may result in facial nerve palsy and gustatory sweating (Frey syndrome)
• Post-surgical wound infection
• Side effects from chemotherapy (such as toxicity), radiation therapy

How is Clear Cell Carcinoma (NOS) of Salivary Gland Treated?

A combination of surgery, chemotherapy, and radiation therapy are used to treat Clear Cell Carcinoma (NOS) of Salivary Gland. The treatment may also depend upon the stage, overall health, age, and grade of the tumor.

The treatment measures for Salivary Gland Clear Cell Carcinoma, NOS may involve:

• Wide surgical excision with removal of the entire lesion is the standard treatment mode
• High-dose radiation therapy may be used after surgery, to destroy the remaining tumor cells
• When the tumor is at an inaccessible location, or is unsafe for surgical intervention, non-invasive procedures, such as chemotherapy and radiation therapy (using fast neutron-beam), may be considered
• Recurrent salivary gland tumors are also known to respond better to fast neutron-beam radiation therapy than other treatment modes
• Embolization is used to provide temporary relief from the symptoms, and reduce blood loss during a surgical procedure
• Clinical trial therapies (especially for stage IV disease) including therapeutic drugs, radiation, stem cell transplantation, and monoclonal antibodies, either singly or in combination of various therapies
• Post-operative care is important: A minimum activity level is to be ensured until the surgical wound heals
• Follow-up care with regular screening and check-ups are important, to watch for recurrence and any metastatic behavior

How can Clear Cell Carcinoma (NOS) of Salivary Gland be Prevented?

• Current medical research has not established a method of preventing the formation of Clear Cell Carcinoma (NOS) of Salivary Gland
• Regular medical screening at periodic intervals with blood tests, radiological scans, and physical examinations, are mandatory for those who have been diagnosed with the tumor
• Due to its high metastasizing potential and chances of recurrence, often several years of active follow-up and vigilance is recommended

What is the Prognosis of Clear Cell Carcinoma (NOS) of Salivary Gland? (Outcomes/Resolutions)

• The prognosis of Clear Cell Carcinoma (NOS) of Salivary Gland is generally excellent with early diagnosis and prompt treatment. No cases of death due to the tumor have been reported
• The prognosis of salivary gland cancer, in general, depends upon a set of several factors that include:
  • Stage of tumor: With lower-stage tumors, when the tumor is confined to site of origin, the prognosis is usually excellent with appropriate therapy. In higher-stage tumors, such as tumors with metastasis, the prognosis is poor
  • The size of the tumor: Individuals with small-sized tumors fare better than those with large-sized tumors
  • Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
  • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
  • Individuals with bulky disease have a poorer prognosis
  • Involvement of the lymph node can adversely affect the prognosis
  • Involvement of vital organs may complicate the condition
  • The surgical resectability of the tumor (meaning, if the tumor can be removed completely)
  • Whether the tumor is occurring for the first time, or is a recurrent tumor. Recurring tumors have worse prognosis compared to tumors that do not recur
  • Response to treatment of salivary gland cancer: Tumors that respond to treatment have better prognosis compared to tumors that do not respond to treatment
  • Progression of the condition makes the outcome worse

Additional and Relevant Useful Information for Clear Cell Carcinoma (NOS) of Salivary Gland:

There are 3 major types of salivary glands and these include the following:

• Parotid glands, found on the sides of the face
• Submandibular glands located at the back of mouth, on both sides of the jaw
• Sublingual glands that are seen under the floor of the mouth

The following article link will help you understand other cancers and benign tumors:

http://www.dovemed.com/diseases-conditions/cancer/