Nasopharyngeal carcinoma caused by ?
Ans. is 'a' i.e., EBV Nasopharyngeal Carcinoma Nasopharyngeal carcinoma is a rare tumor arising from epithelium of the nasopharynx. Nasopharyngeal cancer is uncommon in India except in Noh East region where people are predominantly of Mongoloid origin. People in Southern china, Taiwan and Indonesia are more prone to this cancer. The maximum age incidence is in the fifth decade and the male : female ratio is 2 : 1. Squamous cell carcinoma in various grades of its differentiation or its variants as transitional cell carcinoma and lymphoepithelioma, is the most common (85%). Etiology Nasopharyngeal carcinoma is multifactorial in origin, the three risk factors are :? Genetic : Chinese have a higher genetic susceptibility to nasopharyngeal cancer. Even after migration to other countries they continue to have higher incidence. Viral : Epstein- Bar virus is closely associated with nasopharyngeal cancer. Specific viral markers are being developed to screen people in high incidence areas. Environmental: Air pollution, smoking of tobacco and opium, nitrosamines from dry salted fish, smoke from burning of incense and wood have all been incriminated. Origin and spread The commonest site of origin of nasopharyngeal carcinoma is fossa of Rosenmuller in the lateral wall of nasopharynx.
EBV
HPV
HSV
VZV