10 years old Golden Retriever
History: chronic right inner ear infection
Technique: X-ray, MRI
X-rays: There is thickening and destruction of the right tympanic bullae.
There is marked swelling of the soft tissues of the right aural region. The external ear canal is obliterated and there is calcification of its inner end.
MRI: There is a well-demarcated, expansile mass in the right tympanic bulla, with remodeling and destruction of the right tympanic bone. The right petrous temporal bone and the right inner ear are unclear indicating erosion from the mass. The right external ear canal is not visible. The muscles and tissues on the right side appear markedly hyperintense and there is a fluid filled cavity approximately 6 x 4.4 x 1.9 cm that appears to continue cranially and communicate with right tympanic bulla. This cavity extends from the level of the tympanic bulla and caudally up to the level of the C2 vertebra. The right mandibular salivary gland appears displaced medially from the cavitary lesion.
mass in the right tympanic bulla is consistent with cholesteatoma. Erosion of the right petrous temporal lobe and possible involvement of the inner ear is visible.
Cystic lesion may reflect abcess or haematoma.
Cholesteatoma, a destructive and expanding growth, in the middle ear and/or mastoid process, is a relatively rare cause of otitis media in dogs.
Cholesteatoma are epidermoid cysts lined by a pluristratified keratinizing epithelium containing keratin debris and is characterized by independent and progressive growth, causing destruction of adjacent tissue, especially bone.