Exostoses are seen on otoscopy as discreet single or multiple round shiny swellings deep in the bony external auditory canal (EAC). They are usually asymptomatic, an incidental finding on exam, and extremely slow growing. The inferior canal walls anteriorly and posteriorly are hypertrophied, with a resultant “V” shape. Rarely they enlarge enough to occlude the EAC. They are usually bilateral and are thought to develop in response to repeated cold water exposure, such as frequent swimmer or divers. Hearing loss, ear infection, pain, and tinnitus may arise when they enlarge sufficiently to interfere with the normal self-cleansing of cerumen and desquamated keratin, leading to external otitis or conductive hearing loss from impacted cerumen.
Management and Disposition
Exostoses require no medical or surgical management unless they become symptomatic. Treatment then involves removal of impacted cerumen and/or treating otitis externa if present. For severe or recurrent symptoms, ENT referral for possible surgery is indicated.
Exostosis. Two exostoses are present: a large sessile anterior exostosis and a smaller pedunculated posterior exostosis. The tympanic membrane, malleus handle, and fibrous annulus are visible behind the exostoses. (Photo contributor: Michael Hawke, MD, and The Hawke Library.)
Exostosis is the most common tumor of the EAC.
Use of a Q-tip or examination with an otoscope speculum may cause trauma to the overlying skin in patients with exostosis.
In coastal areas, this condition is often referred to as “surfer’s ear.”
Exostosis. A small sessile exostosis and a pedunculated exostosis are seen. (Photo contributor: Michael Hawke, MD, and The Hawke Library.)