Ear Canal Tumors

What are tumors of the ear canal?
Tumors of the ear canal are abnormal growths that can develop from any part of the ear canal (the skin, the glands of the skin that produce earwax and oil, and the underlying connective tissues, muscles, and bones). Ear canal tumors can be benign or malignant. Benign tumors do not spread, while malignant or cancerous tumors can spread to the surrounding tissues or even other areas of the body (metastasis). Tumors of the external ear canal are more common than tumors of the middle or inner ear.

In dogs, the most common external ear canal tumors are ceruminous gland adenomas (benign) and adenocarcinomas (malignant). Other tumors include inflammatory polyps, papillomas, sebaceous gland adenomas, and more.

In cats, the most common external ear canal tumors are nasopharyngeal polyps, squamous cell carcinomas, and ceruminous gland adenocarcinomas.

Lymphoma, fibrosarcoma, and squamous cell carninomas are occasionally seen in the middle or inner ear of dogs and cats.

What causes these kinds of tumors?
The reason why a particular pet may develop this, or any other tumor or cancer, is not straightforward. Very few tumors and cancers have a single known cause. Most seem to be caused by a complex mix of risk factors, some environmental and some genetic or hereditary. Although there does not appear to be a genetic or hereditary cause for ear canal tumors, chronic inflammation is believed to play a role. German Shepherds and Cocker Spaniels, for example, are at increased risk of developing these tumors. This may be related to the tendency of both breeds to have recurrent and severe ear infections.

What are the clinical signs of ear canal tumors?
horners_syndrome_dog_arrow_2018Initially, these types of tumors may appear as one or more pink, white, or purple nodular masses in the ear canal. If benign, they may grow to a certain size and may or may not be problematic. If malignant, they may grow, ulcerate (break open) and bleed, and nearly invariably become infected, causing recurrent or chronic ear infections. As they grow, they can narrow and even fill (and obstruct) the ear canal.

The most common clinical signs of pets with ear canal tumors include an inflamed, itchy and painful ear, persistent odorous discharge (that can be waxy, pus-filled, or bloody), head shaking, and ear scratching. Sometimes pets will shake or scratch hard enough to cause an ear hematoma (a blood blister). Occasionally draining abscesses may form just below the ear. If the middle or inner ear is involved, pets may experience head tilt, circling, loss of balance and coordination, nystagmus (darting of the eyes back-and-forth), Horner’s syndrome (see photo), facial paralysis (with facial drooping, salivation, and difficulty eating), loss of hearing, and other neurologic signs.
(Image via Wikimedia Commons / Joel Mills (CC BY-SA 3.0.)

How are these kinds of tumor diagnosed?
If deep in the ear canal, these tumors may be difficult to see and therefore diagnose. If the ear canal is severely inflamed, the inflammation may need to be alleviated first to more clearly see the mass. Once the mass is identified, it may (or may not) be possible to take a sample of the tissue, depending on the location. If the mass can be accessed, fine needle aspiration (FNA) or biopsy will be performed. FNA involves taking a small needle with a syringe and suctioning a sample of cells directly from the tumor and placing them on a microscope slide. A veterinary pathologist then examines the slide under a microscope. A biopsy is surgical removal of a piece of the tumor. The tumor tissue is then examined under the microscope. This is called histopathology.

If a diagnosis of malignancy is made from the FNA or biopsy, a CT scan of the head and neck region may be performed to determine how invasive the tumor is and plan a surgical approach. Staging (searching for potential spread to other locations in the body) is highly recommended for malignant tumors, as they tend to spread. This may include bloodwork, urinalysis, X-rays of the lungs, and possibly an abdominal ultrasound. If any lymph nodes appear to be enlarged or firmer than normal, samples may be taken to look for spread.

How do these types of tumor typically progress?
Benign tumors, such as inflammatory polyps, typically only grow to a certain size, but are often irritating and interfere with the ear’s normal function, resulting in waxy buildup and chronic infections. The biggest concern with malignant tumors (other than the possibility of metastasis) is local spread. If the tumor is not treated, it may continue to grow and invade the surrounding tissues, causing pain and increasing the risk of the more serious clinical signs and complications listed above.

What are the treatments for these types of tumor?
The treatment of choice for ear canal tumors is surgical excision. This is curative for benign tumors that are completely removed. Laser surgery may be an option. More extensive surgery is required for malignant ear canal tumors. One procedure, called total ear canal ablation and bulla osteotomy (TECA-BO), involves removing the outer and inner ear canal, as well as the tympanic bulla (the middle ear), leaving only the ear flap remaining.

If complete removal of the tumor is not possible, radiation therapy may be recommended to treat the remaining tumor cells. Radiation therapy may also be recommended for large tumors that cannot be surgically removed, to slow tumor growth or relieve pain. Chemotherapy may be an option if the tumor is highly malignant or if there is evidence of metastasis.

Is there anything else I should know?
It is important to recognize that tumors of the ear canal may grow without much outward evidence, only causing subtle signs in your pet. If your pet suffers from recurrent or chronic ear infections, or shows signs of pain or discomfort, rechecking with your veterinarian at frequent intervals may assist with early detection.

Contributors: Christopher Pinard, DVM
© Copyright 2018 LifeLearn Inc. Used and/or modified with permission under license.
https://vcahospitals.com/know-your-pet/ear-canal-tumors

Total Ear Canal Ablation and Bulla Osteotomy (TECA-BO)

What is a TECA-BO?
The term TECA-BO is an abbreviation for Total Ear Canal Ablation and Bulla Osteotomy. This surgery involves the complete removal of the ear canal and tympanic bulla (middle ear), leaving only the ear flap (pinna) remaining. Typically, this surgery is performed by a specialist, though some veterinarians in general practice may also perform this surgery.


Why would a veterinarian recommend a TECA-BO?
A TECA-BO is primarily recommended in cases of chronic, end-stage otitis (ear infections), in which medical treatment is no longer helping the patient. In some cases, this may be due to a bacterial infection that is resistant to antibiotic treatment; removing the bacteria may be the most effective means of dealing with the infection. In many cases, longstanding infection and inflammation have led to so much scarring and mineralization of the ear canal that the ear canal has narrowed and ear cleaning is no longer effective for removing accumulated debris. In either case, a TECA-BO allows the infected, abnormal ear tissue to be removed, reducing chronic pain and inflammation and giving the pet an improved quality of life.

A TECA-BO may also be recommended in dogs or cats who have neoplastic (cancerous) growths within the ear canal. If the mass is fully confined to the ear canal, a TECA-BO will allow removal of the entire mass.

What does the TECA-BO surgery entail?
Your dog will first undergo a pre-operative assessment. During a physical exam, the veterinarian will assess the extent of your dog’s ear abnormalities and assess the function of those nerves that run adjacent to the ear canal. Pre-anesthetic blood tests will be used to evaluate your dog’s internal organ function prior to anesthesia. Finally, imaging will be performed to evaluate the ear canals and bullae (middle ear). Although X-rays can be used to image the skull and bullae, advanced imaging such as CT scan or MRI are often performed to allow more effective visualization. This pre-operative assessment will assist the surgeons in planning your dog’s surgery.

Your dog will be placed under general anesthesia for surgery. The surgeon will create a skin incision surrounding the ear, then carefully cut through the underlying tissues so that the ear canal can be removed as one intact cylinder. The ear drum and the bones of the middle ear will also be removed. This will expose the middle ear cavity, also known as the tympanic bulla. Infected material will be removed from the bulla and submitted for bacterial culture. This culture will allow identification of the infection-causing bacteria, as well as a determination of the most effective antibiotics for treatment. The bone lining the bulla will be scraped clean and the incision will be closed. An external drain may be left in place at the surgical site, in order to allow remaining fluid/material to exit the incision.

What post-operative care will be required after TECA-BO surgery?

After surgery, your dog may be sent home with a drain still in place. There may also be bandages covering the surgical site. If this is the case, your veterinarian will give you information regarding the proper care and removal of these drains and bandages.

"As the incision is healing, your dog will be required to wear an E-collar (cone)."

Your dog will also go home with both pain medications and antibiotics. Antibiotics are typically continued for 2-4 weeks following surgery, depending on your dog’s overall health status and severity of the ear canal disease.

As the incision is healing, your dog will be required to wear an E-collar (cone). This will keep him from scratching at the surgical site, which could damage the incision and interfere with healing.

What complications are associated with TECA-BO surgery?
The primary risks associated with TECA-BO surgery are associated with the veins and nerves that run in the vicinity of the ear canal. Damage to the blood supply in this area may cause a partial loss of blood supply to the ear flap (pinna). If this occurs, tissue may begin to die along the edges of the ear flap and a second surgery may be required to trim away dead tissues to prevent infection. Damage to the facial nerve may result in paralysis of the affected side of the face. In many cases, this paralysis is temporary and will resolve without treatment, but in some cases the paralysis may be permanent.
Many pet owners expect their dog’s hearing to be reduced after surgery, due to the removal of the ear drum. This is definitely a possibility, but is not always the case. In many cases, the ear canal is so diseased by the time a surgery such as TECA-BO is being considered that owners notice little change in their dog’s ability to hear after surgery.

Some patients (approximately 3-15%) will experience chronic drainage from the incision, indicating the presence of residual infection. This drainage may be noted months to years after the original surgery. Although the drainage will often resolve temporarily with antibiotic treatment, a second surgery is often required for complete resolution.

Overall, the prognosis for pets receiving a TECA-BO is very good. The pet is relieved of a source of chronic pain and inflammation, while the pet owner is relieved of the odor and daily cleaning/medication associated with chronic ear infections.

Contributors: Catherine Barnette, DVM
© Copyright 2017 LifeLearn Inc. Used and/or modified with permission under license.

https://vcahospitals.com/know-your-pet/total-ear-canal-ablation-and-bulla-osteotomy-tecabo