Ear canal osteoma
Osteomas are uncommon. The incidence is estimated to be less than 0.5%. The literature suggests that ear canal osteomas can affect a wide range of age groups starting in the second decade of life. It is estimated that it is more common in males. No clear etiology or risk factors have been linked to their development. These are distinct from exostoses, which have frequent cold water exposure as a risk factor.
The growths are typically asymptomatic unless they are obstructive. On most occasions, they are discovered accidentally during an otoscopic or radiographic exam. If the outgrowth obstructs the ear canal, patients can complain of ear pain, hearing loss, or recurrent outer ear infections. On physical exam, one will see a pearly white, bony outgrowth at the bony-cartilaginous junction in the external ear canal.
Prognosis is excellent. Treatment with surgical excision is only necessary if the patient is symptomatic.
H61.819 – Exostosis of external canal, unspecified ear
277417007 – External auditory canal osteoma
Differential Diagnosis & Pitfalls
- Squamous cell carcinoma – The most common malignant tumor of the EAC.
- Basal cell carcinoma (eg, nodular)
- Exostoses – Smooth sessile protrusions of the medial bony EAC (often anterior and posterior walls), most often multiple and bilateral, common in patients who have had repeated exposure to cold water and wind activities (also known as surfer's ear), more common than osteomas
- Benign polyps – A well-circumscribed, soft, fleshy mass composed of inflammatory tissue, often associated with cholesteatoma or chronic ear infections
- Very uncommon lesions of the ear canal include adenoma, lipoma, fibroma, chondroma, keratoacanthoma, minor salivary gland tumors (benign, malignant) – Diagnosis depends on biopsy.