This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: sinusitis may occur, leading to pus laden nasal discharge and severe headaches. Tumours which obstruct the Eustachian tubes may cause an initially sterile otitis media which can then become colonised and infected. Causes The causes of NPC are unclear. Perhaps surprisingly, tobacco smoking isnt strongly associated with NPC. The aetiology of NPC seems to follow a multi-step process, in which the Epstein-Barr Virus (EBV), ethnic background, and environmental carcinogens all seem to play an important role. It has been shown that EBV DNA was detectable in the plasma samples of 96% of patients with non-keratinizing NPC, compared with only 7% in controls. In adults, other likely etiological factors include genetic susceptibility, consumption of food (in particular salted fish) containing carcinogenic volatile nitrosamines....
View Full Document
- Fall '10