<prompt> Cause of UL secretory otitis media in an adult is -CSOMNasopharyngeal carcinomaMastoiditisForeign body of external ear  <response>: Unilateral serous otitis media in an adult should always raise the suspicion of a benign malignant tumor of nasopharynxIn adults presenting with a unilateral middle ear effusion the possibility of a nasopharyngeal carcinoma should be considered.Ref. Dhingra 5e, p 72, 6e, p 251; Current Laryngology 2e, p 659 