Acute non suppurative otitis media in adults is due to -

A high incidence of NPC (Nasopharyngeal Carcinoma) in Souct East Asia and Southern China correlates with the high incidence of OME (Otitis Media with Effusion) in adults in these regions.” Scotts Brown 7/e, vol 3 p. 3389 "Presence of unilateral serous otitis media in an adult should raise suspicion of nasopharyngeal growth". Ref. Dhingra 6/e p 257