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Ceruminous Gland Ear Tumours

in cats

“Yoda” was a wonderfully affectionate, thirteen-year-old, male Ginger cat. He had been brought in on several occasions with symptoms of recurrent ear infections. These infections were becoming more and more frequent, and on a thorough scoping of his ear canals it was noted that he had developed lesions, numerous blueish masses, within both of his ear canals.

These masses were clearly obstructing the ear canals and were undoubtably the cause of his recurrent ear infections. “Yoda” had symptoms of Ceruminous Gland ear tumours. 

Ceruminous glands are located within the deeper skin layers of the external ear canal. The most common tumour of the ear canal is ceruminal gland in origin, and these neoplasms are more common in the cat than in the dog. Ceruminous gland tumours are a neoplasia of the apocrine sweat glands found in the external ear canal. They affect older cats most commonly and can be benign or malignant. 

Ceruminous mass lesions may develop because of chronic inflammations and ear infections: otitis externa; as a degenerative change in older cats; or, in some cases, it can be a congenital condition.  

Signs include a very smelly ear, or ears, an ear discharge, head shaking and scratching of the ears, bleeding from the affected ear canal if the masses are self-traumatised, and a history of recurrent ear infections, particularly in older cats. 

One report has noted that tumours of the ceruminous glands accounted for over 40% of external ear masses evaluated in cats, and that they are most often benign, non-cancerous, adenomas. Malignant, cancerous, ceruminous gland tumours, termed adenocarcinoma lesions, tend to be more destructive ulcerative and infiltrating to surrounding tissues, for example to the surrounding lymph nodes, salivary glands, and the middle ear, rather than the simply obstructive and occlusive lesions to the ear canal caused by benign adenomas. Also, malignant tumours tend to affect one ear and benign masses tend to affect both ears. 

The classic appearance of ceruminous adenoma masses is of multiple, often numerous, punctuate nodules, lumps, or vesicles, starting at usually less than 2mm in diameter, within the external ear canal and on the inner ear flap or “pinna”. They are generally a darkish blue, brown or a greyish blue-black in colour. They are usually confined to the external ear canal, and rarely extend beyond the vertical canal of the ear. 

A confirmed diagnosis is based on a histological examination of biopsied tissue samples at a Veterinary Laboratory.  

Treatment depends on the severity of the mass lesions and on how much they are occluding the affected ear canals. The best treatment for your cat will depend on many factors, including the type and location of the tumour. Topical treatments can relieve the secondary ear infection symptoms and any inflammation. Also, as research shows that food allergies can also play a role in ceruminous gland otitis and thus ceruminous gland hyperplasia, a food trial with a hydrolysed protein or novel protein diet can be trialled for a minimum of eight weeks.  

Surgery of benign ceruminous gland adenomas is usually reserved for more severe cases to remove the multiple ceruminous gland nodules if they are occluding the ear canal. Surgical options include a lateral ear canal resection or total surgical ablation of the affected ear canal and surgical removal of the affected ear flaps to allow a more open ear canal and increased comfort for the patient. Specialist Laser therapy is also an effective therapy which enables laser ablation of the tumours with little collateral tissue damage and limit removal to just the lesion, thereby avoiding damage to adjacent normal structures. Surgery or laser treatment are followed up with regular ear cleaning and topical corticosteroid drops, to try to minimise recurrence of the cysts. 

“Yoda” had biopsy samples taken of his ear tumours, and thankfully these lesions were diagnosed as benign adenomas. He did have multiple lesions occluding both of his ear canals and causing him recurrent ear infections and discomfort, so he was referred for specialist soft tissue surgeries.  

“Yoda” had ear canal ablation surgeries done on both his ears, these surgeries were done over a period of a months, with a healing gap allowed for him between each ear surgery. After his procedures he had on-going daily ear drops and regular ear cleaning and check-ups at the practice. 

After healing from his surgeries “Yoda” had no further ear infections, and he was so much more comfortable and lived a happy life into older teenage years. 

If your cat has had recurrent, refractory ear infections, or you note any unusual mass lesions within your cats’ ears, please do arrange an appointment for a check-up appointment at your Vet practice.  

Alison Laurie-Chalmers
Senior Consultant
Crown Vets