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
CSOM
Nasopharyngeal carcinoma
Mastoiditis
Foreign body of external ear