Nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a tumor arising from the epithelial cells that cover the surface and line the nasopharynx. The annual incidence of NPC in the UK is 0.3 per million at age 0-14 years, and 1 to 2 per million at age 15-19 years. Incidence is higher in the Chinese and Tunisian populations. Although rare, NPC accounts for about one third of childhood nasopharyngeal neoplasms. Three subtypes of NPC are recognized in the World Health Organization (WHO) classification: 1) squamous cell carcinoma, typically found in the older adult population; 2) non-keratinizing carcinoma; 3) undifferentiated carcinoma. The tumor can extend within or out of the nasopharynx to the other lateral wall and/or posterosuperiorly to the base of the skull or the palate, nasal cavity or oropharynx. It then typically metastases to cervical lymph nodes. Cervical lymphadenopathy is the initial presentation in many patients, and the diagnosis of NPC is often made by lymph node biopsy. Symptoms related to the primary tumor include trismus, pain, otitis media, nasal regurgitation due to paresis of the soft palate, hearing loss and cranial nerve palsies. Larger growths may produce nasal obstruction or bleeding and a "nasal twang". Etiological factors include Epstein-Barr virus (EBV), genetic susceptibility and consumption of food with possible carcinogens--volatile nitrosamines. The recommended treatment schedule consists of three courses of neoadjuvant chemotherapy, irradiation, and adjuvant interferon (IFN)-beta therapy.