Pathology of ceruminous gland adenoma associated with Staphylococcus epidermidis otitis externa in a cat

A two-year old intact domestic male cat (Felis catus) was presented in the Veterinary Clinical Complex, Dr G.C. Negi College of Veterinary and Animal Sciences, Palampur, Himachal Pradesh with a history of continuous unilateral purulent discharge from the right ear canal along with the signs of otalgia and hyperemia of the infected area. There was continuous head shaking and scratching of the infected ear. Otoscopic examination revealed the presence of three different growths of irregular shapes partially obstructing the right ear canal. Biopsy sample from the growths present in the ear canal of a cat was submitted to the Department of Veterinary Pathology. Gross examination of the growth revealed pigmented, friable and pale growths which were smooth in appearance. Cytological examination was suggestive of fibrinopurulent inflammation associated with bacterial infection in addition to the presence of clusters of columnar to round cells showing moderate pleomorphism, hyperchromasia, increased nuclear to cytoplasmic ratio and prominent nucleoli. Masson’s trichrome staining revealed the presence of fibrous tissue capsule around the tumor. Histopathological examination revealed columnar epithelial cells lining the glandular lumen showing moderate pleomorphism, hyperchromasia, increased nuclear to cytoplasmic ratio, prominent nucleoli and loss of polarity along with the presence of very few mitotic figures. Cytological, gross and histopathological findings confirmed the case of ceruminous gland adenoma associated with external ear infection of Staphylococcus epidermidis in a cat.