Cancer Health Center

The nasopharynx has a cuboidal shape. The lateral walls are formed by the eustachian tube and the fossa of Rosenmuller. The roof, sloping downward from anterior to posterior, is bordered by the pharyngeal hypophysis, pharyngeal tonsil, and pharyngeal bursa with the base of the skull above. Anteriorly, the nasopharynx abuts the posterior choanae and nasal cavity, and the posterior boundary is formed by the muscles of the posterior pharyngeal wall. Inferiorly, the nasopharynx ends at an imaginary horizontal line formed by the upper surface of the soft palate and the posterior pharyngeal wall.

Unlike other squamous cell cancers of the head and neck, nasopharyngeal cancer does not appear to be linked to excess use of tobacco and alcohol. Factors thought to predispose to this tumor include Chinese (or Asian) ancestry, Epstein-Barr virus (EBV) exposure,[1] and as yet unknown factors that result in very rare familial clusters.[2]

Symptoms and signs at presentation include painless, enlarged lymph nodes in the neck (present in approximately 75% of patients and often bilateral and posterior), nasal obstruction, epistaxis, diminished hearing, tinnitus, recurrent otitis media, cranial nerve dysfunction (usually II–VI or IX–XII), sore throat, and headache. In the patient who presents with only cervical adenopathy, the finding of EBV genomic material in the tissue after amplification of DNA with the polymerase chain reaction lends strong evidence for a nasopharyngeal primary tumor, and a concerted search should be conducted in that area.[3]

Tumors of many histologies can occur in the nasopharynx but this discussion, like the American Joint Committee on Cancer nasopharynx staging, refers exclusively to those of squamous cell type.

Diagnosis is made by biopsy of the nasopharyngeal mass. Workup includes careful visual examination (by mirror or endoscopic examination); documentation of the size and location of the tumor and neck nodes; evaluation of cranial nerve function and hearing; skull films (especially base of skull views), evaluating neural foramina; complete computed tomographic (CT) scan or magnetic resonance imaging (MRI) with views delineating the upper and lower extent of the lesion; chest x-ray; hemogram; and chemistry panel. Any clinical or laboratory suggestion of distant metastasis may prompt further evaluation of other sites. Careful dental and oral hygiene evaluation and therapy is particularly important prior to initiation of radiation treatment. MRI is often more helpful than CT scans in detecting abnormalities and in defining their extent.[4,5,6]

Major prognostic factors adversely influencing outcome of treatment include large size of the tumor, higher T stage, and the presence of involved neck nodes.[7] Other factors linked to diminished survival that were present in some, but not all, studies include age, nonlymphoepithelial histology, long interval between biopsy and initiation of radiation therapy, diminished immune function at diagnosis, incomplete excision of involved neck nodes, pregnancy during treatment, locoregional relapse, and certain EBV antibody titer patterns.