Unusual causes of unilateral serous otitis media.

Two cases of nonkeratinizing squamous cell carcinoma (transitional cell carcinoma), both of which arose in the Eustachian tube, and two cases of neurilemoma of the nasopharynx are reported. All four patients presented with unilateral serous otitis media. The duration of the unilateral serous otitis media in these patients ranged from 1 1/2 to 8 years. This emphasizes the fact that adult patients with unilateral serous otitis media without a history of an upper respiratory tract infection or of barotrauma should undergo thorough examination to rule out the presence of an unusual underlying pathologic condition.