Exostosis of the ear is a condition where there is benign overgrowth of bone within the ear canal. It is commonly known as surfer’s ear as it tends to occur in patients who have spent a significant amount of time in cold water e.g surfing. Exposure to cold water is thought to cause increased vascularity in the growth centres for bone in the ear, leading to the excess growth.
The exostoses usually appear as smooth mounds within the ear canal with normal skin covering. There is usually more than one exostosis in the ear canal and it is not uncommon for both sides to be affected.
Exostosis is distinct from a much less common bony growth in the ear canal known as an osteoma. This slow growing bony tumour that is benign. There is usually only one bony lump affecting only one ear. Unlike exostosis, the formation of osteoma is not associated with cold water exposure.
Exostosis or osteoma of the external ear may cause narrowing of the ear canal, leading to buildup of wax and obstruction of the ear canal. If the problem is recurrent, persistent or leads to complications e.g infection or impairment of hearing, they can be removed surgically. Precise removal of the bony growth requires visualisation with an operating microscope and specialised micro-instruments for operation in the ear.