Nasopharyngeal carcinoma. Brief review.

Nasopharyngeal carcinoma has a well-defined geographic distribution, primarily affecting persons from southern China and Southeast Asia. Environmental factors are numerous and appear to have a secondary role, mainly in the promotion of the neoplastic process. Relationship with the Epstein-Barr virus is indicated by the identification of viral genome copies within the cells and by a persistent host antibody response with restricted specificity for nasopharyngeal malignancies. The World Health Organization has recently adopted a histologic classification categorized into three subtypes according to the degree of epithelial differentiation, keratinization, and stromal lymphocytic infiltration. The tumor expands locally to contiguous structures, spreads through the cervical lymphatics following the jugular chain, and eventually metastasizes to the skeleton and liver. Primary management consists of radiation therapy to cervicofacial fields and usually offers adequate palliation, with a five-year median survival of 67 percent for stage I and 17 percent for stage IV disease.