Exostoses are smooth bony prominences that can be detected under the healthy skin in the bony part of the ear canal.
Cholesteatoma of the ear canal resembles an occluding plug of earwax, but has a pearly surface.
Many inflammatory changes affecting the middle ear may protrude into the ear canal through a tympanic membrane perforation.
Malignant tumours of the ear canal are rare but should be considered, for example, in the differential diagnosis of refractory otitis media.
Lesions of the ear canal
Exostosis of the bony ear canal
The most common change affecting the ear canal
Cold water in the ear canal irritates the periosteum resulting in increase of bone growth locally.
Also called "surfer's ear”. Notice that the English term "swimmer's" ear may refer either to exostosis or to otitis externa.
A convex bony prominence is noted under the healthy skin near the tympanic membrane.
Usually asymptomatic. A large exostosis may, together with earwax, obstruct the ear canal and cause conductive hearing loss.
Using earplugs during exposure to cold water may prevent the development of exostosis.
Most exostoses need no treatment, but those causing symptoms can be removed surgically.
Ear canal cholesteatoma
An accumulation of keratinising squamous epithelium often associated with erosion of the bony ear canal
Rare
A cholesteatoma resembles impacted earwax, but it is partially light coloured and has a pearly appearance.
Treatment consists of repeated microscopic cleaning and, if necessary, surgical removal.
Other lesions
Any finding observed in the middle ear, such as a polyp, granulation tissue or a cholesteatoma, may also originate from the middle ear.
In such a case, the lesion usually protrudes from the middle ear through a perforation in the tympanic membrane.
The removal of a mass in the ear canal is carried out by a specialist physician, as is the management of any underlying condition, such as chronic otitis media or cholesteatoma in the middle ear.
Benign tumours
Osteoma
Benign bone tumour
Far more infrequent than an exostosis
An osteoma is usually pedunculated and causes no symptoms until it obstructs the ear canal.
Treatment by a specialist, based on case-by-case consideration.
Adenoma
Originates from a gland that produces cerumen.
Malignant tumours
Very rare
Most malignant tumours of the ear canal are squamocellular carcinomas. Their appearance resembles squamocellular carcinomas of the skin. Basal cell carcinomas are more infrequent.
Adenocarcinoma is a malignant tumour that originates from the glands that produce cerumen.
There may also be a melanoma in the skin of the ear canal.
Pain and otitis externa are the common symptoms.
Refractory, recurrent and especially unilateral and localized otitis externa warrants a biopsy so that a malignant tumour can be excluded and the delay in treatment of a possible malignant tumour minimized.
Malignant tumours of the ear canal are treated in ear, nose and throat clinics specialized in the treatment of head and neck tumours.
References
Kaminska-Winciorek G, Slowinska M, Krotowski J, et al. Dermoscopy of external ear melanoma (EEM). Arch Dermatol Res 2023;315(5):1381-1387. [PubMed]
Sandison A. Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumours: Tumours of the Ear. Head Neck Pathol 2022;16(1):76-86. [PubMed]
Nicoli TK, Atula T, Sinkkonen ST, et al. Ear canal and middle-ear tumors: a single-institution series of 87 patients. Acta Otolaryngol 2022;142(2):132-139. [PubMed]
Allanson BM, Low TH, Clark JR, et al. Squamous Cell Carcinoma of the External Auditory Canal and Temporal Bone: An Update. Head Neck Pathol 2018;12(3):407-418. [PubMed]
Hertz J, Siim C. External auditory canal cholesteatoma and benign necrotising otitis externa: clinical study of 95 cases in the Capital Region of Denmark. J Laryngol Otol 2018;132(6):514-518. [PubMed]
Thompson LD. Update From the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Tumours of the Ear. Head Neck Pathol 2017;11(1):78-87. [PubMed]
Morris S, Martin T, Mccahon D, et al. Awareness and attitudes towards external auditory canal exostosis and its preventability in surfers in the UK: cross-sectional study. J Laryngol Otol 2016;130(7):628-34. [PubMed]
Attlmayr B, Smith IM. Prevalence of 'surfer's ear' in Cornish surfers. J Laryngol Otol 2015;129(5):440-4. [PubMed]