Nasopharyngeal cancer is a rare type of head and neck cancer in which malignant (cancer) cells form in the tissues of the nasopharynx. The nasopharynx is the upper part of the pharynx (throat) behind the nose. The pharynx is a hollow tube about 5 inches long that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes from the throat to the stomach). Air and food pass through the pharynx on the way to the trachea or the esophagus. The nostrils lead into the nasopharynx. An opening on each side of the nasopharynx leads into an ear. Nasopharyngeal cancer most commonly starts in the squamous cells that line the nasopharynx. See Head and Neck Cancers for signs, symptoms and treatments.