Nasopharyngeal cancer develops in the nasopharynx, an area in the back of the nose toward the base of skull. The nasopharynx is a box-like chamber about 1˝ inches on each edge. It lies just above the soft palate, just in back of the entrance into the nasal passages. Although it is considered an oral cancer, nasopharyngeal cancer is different from most oral cancers. It tends to spread widely, is not often treated by surgery, and has different risk factors from most oral cancers.

Several types of tumors can develop in the nasopharynx. Some of these tumors are benign (non-cancerous). Others are malignant (cancerous), and these can penetrate into surrounding tissues and spread to other parts of the body.

Benign nasopharyngeal tumors: Benign tumors of the nasopharynx are relatively rare and tend to occur in children and young adults. They include tumors or malformations of the vascular (blood-carrying system) such as angiofibromas and hemangiomas, and benign tumors of the minor salivary glands that are found within the layers of the nasopharynx. It is important to discuss what type of tumor you might have with your doctor.

Malignant nasopharyngeal tumors: Although other types of cancers can arise from the tissues that make up the nasopharynx, nasopharyngeal carcinoma (NPC) is the most common malignant tumor of the nasopharynx. The remaining sections of this document refer exclusively to NPC.

There are 3 types of NPC: keratinizing squamous cell carcinoma (type 1), non-keratinizing carcinoma (type 2); and undifferentiated carcinoma (type 3). The frequency of these different types varies with geographical area. Most NPC in the United States is the keratinizing type. In Southeast Asia, where NPC is much more common, most cases are the undifferentiated type (see Key Statistics Section). Although these types look different under a microscope, studies have shown they arise from the same cell type – the lining cell of the nasopharynx. The treatment is also usually the same for all types. How far the NPC has spread locally and throughout the body (stage) is often more important than its type in predicting the outlook for chances of survival (prognosis).

All subtypes of NPC develop from the epithelial cells that cover the surface lining of the nasopharynx. Many nasopharyngeal carcinomas also contain lots of immune system cells, especially lymphocytes. The term lymphoepithelioma is sometimes used to describe an NPC with many immune system cells (lymphocytes) among the cancer cells. The presence of these immune system cells does not usually affect the choice of treatment options. But they may be a clue to developing new treatments since they may represent the body’s attempt to “reject” the tumor (for more, see, "What's New in Nasopharyngeal Cancer Research and Treatment?").

Lymphomas can also be found in the nasopharynx. They are cancers of immune system cells called lymphocytes, cells that are normally found in the nasopharynx. These cancers are discussed in the American Cancer Society document on "Non-Hodgkin Lymphoma in Adults."

Adenocarcinoma and adenoid cystic carcinoma may develop in the minor salivary glands found in the nasopharynx but are more commonly found in the nasal or oral cavities. These minor salivary gland cancers are discussed in the American Cancer Society documents on "Oral Cavity and Oropharyngeal Cancer" and "Nasal Cavity and Paranasal Cancer." Last Revised: 08/03/2006