Cause of U/L secretory otitis media in an adult is -

Unilateral serous otitis media in an adult should always raise the suspicion of a benign / malignant tumor of nasopharynx “In adults presenting with a unilateral middle ear effusion the possibility of a nasopharyngeal carcinoma should be considered”. Ref. Dhingra 5/e, p 72, 6/e, p 251; Current Laryngology 2/e, p 659