What is squamous cell carcinoma in cats?


Squamous cells are cells that make up the outer layer of the epithelium, the tissue that lines the external and internal surfaces of organs. Squamous cell carcinoma (SCC) is a tumour that affects these cells. SCC most commonly affects cats as skin or oral tumours and can be found in the ear pinnae, nose, nail beds, corners of the eyes and mouth.


What does squamous cell carcinoma look like in cats?

Skin SCC tumours are typically small, poorly outlined lesions that may be associated with surrounding hair loss and skin inflammation. Lesions are likely to be ulcerated and ooze fluid. As the tumour progresses, you’ll notice swelling and more ulceration. Eventually, the tumour may metastasize to other parts of the body. In the early stages, oral SCC can appear similar to dental disease. The gums become ulcerated and teeth loosen as cancer invades the jaw, and these early signs may be missed.


How do cats develop squamous cell carcinoma?

Most SCC cases develop as a result of environmental or genetic risk factors. The most common cause is excessive sun exposure but also can include chemicals, specific viruses, physical trauma, and burns. Light-coloured and white cats are most likely to develop SCC because of the lack of protective pigment in their skin.


How is squamous cell carcinoma diagnosed and treated in cats?

Squamous cell carcinoma can be diagnosed through a biopsy, which usually requires general anesthesia. At that time, the tumour may be completely removed to reduce the need to put the cat under anesthesia again. In some cases, surgical removal can cure skin SCC. In other instances, radiation therapy, cryotherapy, laser ablation, photodynamic therapy, or chemotherapy may be successful treatment options. The prognosis is generally good if the tumour is removed in the early stages and has not had a chance to spread, but close monitoring is critical to watch for recurrence.


If your cat develops a suspicious oral lesion, skin lesion, begins to drool excessively or refuses food, schedule an appointment with your veterinarian for further evaluation.