The roof, sloping downward from anterior to posterior, is bordered by the pharyngeal hypophysis, pharyngeal tonsil, and pharyngeal bursa with the base of 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. 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.
Diagnosis is made by biopsy of the nasopharyngeal mass.
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. Patients with advanced lesions, especially those associated with clinically positive cervical lymph nodes, cranial nerve involvement, and bone destruction, are poorly controlled locally by radiation therapy with or without surgery and often develop distant metastases despite local control. The incidence of second primary malignancies appears less than other head and neck sites.