Nasal tumors occur primarily in the nasal cavity and may later extend to the frontal and paranasal sinuses. Nasal tumors form a very small percentage of feline tumors and are less common than nasal cancer in dogs. They are locally invasive and do not normally spread but are almost always malignant. They are not sex specific and usually occur at a young age.
In cats, there is an indication that inflammation of the mucus membrane lining the nose or one of the paranasal sinuses may be the trigger that leads to a growth in the nasal cavity. Symptoms of nasal cancer in cats can remain concealed for as long as five years until the disease presents itself as a serious threat. Unlike the symptoms of liver cancer in dogs, symptoms of nasal cancer seldom mimic symptoms of other conditions.
Nasal tumors and nasopharyngeal tumors reflect different symptoms. Nasal tumors often have a past history of nasal discharge and sneezing. Nasopharyngeal tumors, on the other hand, manifest as heavy breathing, often with a snoring sound and change in vocalism. Other signs include bleeding and facial deformity.
The veterinarian would look for clinical signs of nasal or nasopharyngeal tumors. If the clinical findings point towards these tumors, laboratory tests and imaging is done to investigate further to confirm or rule out cancer.
- Complete blood tests sometimes reveal concurrent symptoms associated with nasal cancer, such as an abnormally low platelet count.
- Cytological examination of an aspirate of the local lymph node
- Radiography of the thorax is done to obtain three views to rule out metastasis to the lungs.
- Imaging of the area with CT scan, MRI or radiography of the nasal cavity
The two most common types of nasal tumors in cats are lymphoma (cancer of the lymph tissue) and carcinoma (cancer of the epithelial tissue). Chemotherapy is reasonably effective mode of treatment for nasal lymphoma, but cats with feline leukemia virus are at a risk of systemic failure. An aggressive treatment for nasal lymphoma should be a combination of local radiation and systemic chemotherapy.
Studies reveal that carcinomas in the nasal cavity treated with surgery have resulted in an average survival time of 2 to 5 weeks. The results of irradiation on nasal tumors have not been studied extensively. The nasal cavity of cats is deep and nasal tumors may be difficult to approach for removal. Radiation alone may be effective for treating nasal tumors using orthovolatage and megavoltage radiation therapy. For accessible tumors, surgery before radiation may be the recommended treatment.
Nasal cancer presents a poor prognosis irrespective of the stage it has advanced. Side effects of radiation result in persistent change in the turbinate bones and ophthalmic and corneal ulcerations. Surgery, on the other hand, does not improve the survival time and owners are often forced to consider euthanasia within two to eight weeks.