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Squamous Cell Carcinoma of Nasal Planum in Dogs

The epithelium is the cellular covering of all of the internal and external surfaces of the body, protecting the organs, inner cavities and outer surfaces of the body in a continuous layer of multi-layered tissue. The squamous epithelium is a type of epithelium that consists of the outer layer of flat, scale-like cells, which are called squamous cells.

In this case, squamous cell carcinoma of the nasal planum arises from the tissue in the nose pad, or in the mucous membranes of the nose. A squamous cell carcinoma is a malignant tumor of the squamous epithelial cells, but in the case, the risk of malignant metastasis is relatively low. It is often more invasive that metastatic. Exposure to inhaled chemicals increases the risk of nasal tumors, including indoor use of coal, cigarettes, and air fresheners.

This tumor is rare in dogs as compared to cats. There does not appear to be any particular breed, gender or age that is more susceptible, but it is suspected that dogs with larger nasal passages may be at higher risk, and dogs with light pigmented noses are at risk. A lot of time spent in the sun can also increase the risk.

Symptoms and Types

• This tumor progress slowly, often starting as a superficial crust and scab
• Decreased air through the nose (i.e., more mouth breathing)
• Sneezing and reverse sneezing (i.e., sudden, involuntary inward breaths)
• Nosebleeds (epistaxis)
• Nasal discharge
• Swelling of involved area, including swelling of the eye, loss of sight
• Facial deformity
• Excessive tears from eyes (epiphora)
• Neurological signs (from pressure on brain) – seizure, disorientation, behavioral changes

Causes

• Exposure to excessive sun light
• Absence of protective pigment
• Exposure to toxic inhalants

Diagnosis

You will need to give your veterinarian a thorough medical history of your dog's health and onset of symptoms. Your veterinarian will perform a physical examination with full laboratory testing, including complete blood tests, biochemical profiles, and urinalysis. The results of these tests are usually normal in affected patients. While metastasis is rarely seen in the lungs, your veterinarian may take thoracic x-rays to evaluate for metastasis into the lungs. Other conditions your doctor will look for are dental diseases, aspergillosis, bacterial rhinitis, foreign object (such as a plant awn), and parasites (such as mites).

For an appropriate diagnosis to be made, your veterinarian will need to take tissue and fluid samples from the affected area. Your veterinarian will also take samples from the lymph nodes to detect whether metastasis is occurring. Magnetic resonance imaging (MRI) and computed tomography (CT) scans may provide more information about the extent of the tumor, as well as to help in surgical resection of the tumor.