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Cancer begins when cells in the body become abnormal and multiply without control or order. These cells form a growth of tissue, called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous).
Nasopharyngeal cancer (also called nasopharyngeal carcinoma or NPC) is a disease of the nasopharynx, which is the air passageway at the upper part of the pharynx (throat) behind the nose. The pharynx is a hollow tube approximately five inches long that starts behind the nose and ends on top of the larynx (or voice box) and esophagus (the swallowing tube that goes from the throat to the stomach). The nostrils lead through the nasal cavity into the nasopharynx, and an opening on each side of the nasopharynx (called the Eustachian tube opening) leads into the middle ear on each side.
Types of nasopharyngeal tumors
There are several types of benign nasopharyngeal tumors, including angiofibromas and hemangiomas that involve the vascular (blood-carrying) system and tumors in the lining of the nasopharynx that include the minor salivary glands.
A malignant nasopharyngeal tumor is cancerous. This means it can invade and damage healthy tissues and organs in other parts of the body. The nasopharynx contains several types of tissue, and each contains several types of cells. Different cancers can develop in each kind of cell. The differences are important because they determine the seriousness of the cancer and the type of treatment needed. According to the World Health Organization (WHO), NPC is classified into three subtypes:
- Keratinizing squamous cell carcinoma (WHO type 1)
- Nonkeratinizing squamous cell carcinoma (WHO type 2)
- Undifferentiated or poorly differentiated carcinoma, including lymphoepithelioma and anaplastic variants (WHO type 3). Many types of nasopharyngeal cancer contain white blood cells, and these lymphocytes give it the name of lymphoepithelioma. (See more details about differentiation in the Staging section.)
NPC is one of five main types of cancer in the head and neck region, a grouping called head and neck cancer.
Find out more about basic cancer terms used in this section.
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