What is a nasal tumor?
A nasal tumor is a type of cancer that results from the disorganized and uncontrolled production of cells that line the nasal airways. In dogs, the most common nasal tumor is nasal adenocarcinoma. Nasal adenocarcinomas arise from glandular cells (eg, sebaceous glands) in the nasal cavity. In cats, the most common nasal tumor is nasal lymphoma
what causes this cancer?
The reason a particular pet might develop this or any type of cancer is not straightforward. very few cancers have a single known cause. most appear to be caused by a complex combination of risk factors, some environmental and some genetic or hereditary. in the case of nasal tumors, exposure to cigarette smoke and living in urban environments seem to be risk factors. in cats, the risk may increase with exposure to certain viruses. cats with a history of feline leukemia virus or feline immunodeficiency virus may be predisposed to developing lymphoma, including nasal lymphoma.
Reading: Early stage cancer on dogs nose
what are the clinical signs of nasal tumors?
Most pets with nasal tumors have nasal discharge (usually pus-like or with streaks of blood) from one or both nostrils, noisy breathing (from blocked airflow), cough, lethargy, and weight loss . Some pets, especially cats, will develop facial deformities as the tumor grows. neurologic signs (eg, seizures, sudden onset of blindness, circling, muscle weakness, and behavioral changes) are rare but may be the only signs seen.
How are nasal tumors diagnosed?
Nasal tumors are usually diagnosed using imaging (X-rays, CT scans, or MRIs) of the nasal area. the images are especially helpful in determining the size and location of the tumor. To identify the type of tumor, a wash of the nasal cavity can be performed. cells collected in the fluid are examined under a microscope. if the nasal wash does not provide a diagnostic sample, a biopsy (surgical removal of a part of the tumor) will be required. the part(s) of the tumor are examined under a microscope. this is called histopathology.
how does this cancer usually progress?
Although less than 25% of pets will show signs of spread to local lymph nodes, routine staging (searching for possible spread to other parts of the body) is strongly recommended. this may include blood tests, urinalysis, repeated X-rays or CT scans of the lungs, and possibly an abdominal ultrasound. Fine-needle aspiration (FNA) of local lymph nodes is usually recommended. fna involves taking a small needle with a syringe and sucking out a sample of cells directly from the lymph node and placing them on a slide. A veterinary pathologist then examines the slide under a microscope.
Even with a low tendency to spread to other sites, these tumors have a high tendency to spread locally. Because they spread, are often painful, and can affect the brain (since the nasal cavity is so close to the brain), treatment is very important as soon as a diagnosis is made. treatment can control the tumor and relieve signs. if the nasal tumor is part of a systemic disease (eg, lymphoma in cats), various signs may develop depending on the organs and body parts affected. again, prompt treatment is helpful in controlling the tumor and relieving signs.
what is the treatment for this type of tumor?
The treatment of nasal tumors depends on the specific type of tumor. radiotherapy is the treatment of choice for dogs with adenocarcinoma. radiation therapy can provide excellent tumor control as well as relief of clinical signs. lymphomas, especially in cats, are also treated with radiation. however, since lymphoma is usually a systemic disease, tests should be done to make sure it is not present elsewhere. if so, chemotherapy is often sought instead. Regardless, lymphoma is sensitive to both radiation and chemotherapy, and your veterinarian (or veterinary oncologist) will recommend the best course of treatment for your pet.