Nasopharyngeal carcinoma is a rare tumor of the epithelial layer lining the nasopharynx. It can occur at any age, although most reported cases are in the age group 50-60 years. Children may also be affected, but very rarely. Nasopharyngeal carcinoma accounts for less than 1% of all childhood malignancies. Some parts of the world have been considered as endemic areas where nasopharyngeal cancer comprises 18-25% of all cancers such as southern China, Hong Kong, Taiwan, Kenya, the Philippines, Singapore, Tunisia, Sudan and Uganda. In general, the disease is more predominant in males with a male: female ratio of 2:1. Based on microscopic findings, nasopharyngeal carcinoma is classified into three types. Type I is squamous cell carcinoma which comprises 25% of nasopharyngeal carcinomas and is typically found in the older adult population. The second type (type II) is known as non-keratinizing carcinoma that involves 12% of the cases with nasopharyngeal carcinoma. About 60% of the patients have type III, or undifferentiated carcinoma, which includes lymphoepitheliomas, anaplastic, clear cell, and spindle cell variants. Patients usually present trismus, pain, otitis media, nasal regurgitation due to paresis of the soft palate, hearing loss and cranial nerve palsies.
Nasopharyngeal carcinoma is a multifactorial disease linked to genetic and environmental factors, as well as viral infection (Epstein-Barr virus). Multiple loci have been identified that show association with nasopharyngeal carcinoma predisposition. These include 4p, 6p21, and MST1R gene on chromosome 3p21.