Nasopharyngeal cancer develops in the nasopharynx, an area in the back of the nose toward the base of skull.
The nasopharynx is the upper part of the throat (pharynx) that lies behind the nose. It is a box-like chamber about 1½ inches on each edge. It lies just above the soft part of the roof of the mouth (soft palate) and just in back of the entrance into the nasal passages.
Several types of tumors can develop in the nasopharynx. Some of these tumors are benign (non-cancerous), but others are malignant (cancerous). It is important to discuss what type of tumor you might have with your doctor.
1. Benign nasopharyngeal tumors
Benign tumors of the nasopharynx are fairly rare and tend to occur in children and young adults. They include tumors or malformations of the vascular (blood-carrying) system. If you have one of these tumors, you and your doctor will talk about what
treatments might be appropriate for you.
2. Malignant nasopharyngeal tumors
These tumors can invade surrounding tissues and spread to other parts of the body.
3. Nasopharyngeal carcinoma (NPC)
This is by far the most common malignant tumor of the nasopharynx. A carcinoma is a cancer that starts in epithelial cells — the cells lining the internal and external surfaces of the body.
There are 3 types of NPC:
· Keratinizing squamous cell carcinoma
· Non-keratinizing differentiated carcinoma
· Undifferentiated carcinoma
Each of these types is more common in some areas of the world than in others. 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.
These types look different when seen under a microscope, but studies have shown they start from the same cell type — the epithelial cells that cover the surface lining of the nasopharynx. The treatment is also usually the same for all types of nasopharyngeal cancer. The stage of the cancer — how far it has grown and spread — is often more important than its type in predicting a person’s outlook (prognosis).
Many nasopharyngeal carcinomas also contain lots of immune system cells, especially lymphocytes. The term lymphoepithelioma is sometimes used to describe an NPC with many lymphocytes among the cancer cells. The presence of these 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.