Squamous Cell Carcinoma in Pets

It’s a strange time of year to be talking about skin cancer, but…

I noticed a funny spot on my cat’s eye the other day. Chewy had some weeping from that eye of late, but the fields were being cut, the leaves were falling- generating mold, the windows were closed, stifling the air. I convinced myself that allergies were the reason for the discharge. Besides, it was a clear drainage, not yellow or green. Just a runny eye.

But it never went away, despite my multiple ministrations. Finally, I drove my cat across the bridge to Anne Weight, a veterinary ophthalmologist in Annapolis who instantly diagnosed a tumor. Looking through a high-powered magnification scope, she could see an ulcer on Chewbacca’s lid margin. Because she felt strongly that this was Squamous Cell Carcinoma, she took him to surgery the next day to remove that part of his lower eyelid. The biopsy confirmed her suspicion and we did a further treatment, cryotherapy to freeze and destroy any remaining tumor cells. Chew went home that same day with eye drops and pain meds. Two months later, he’s looking good and feeling hungry!

Squamous cell carcinoma (SCC) is of course, a form of skin cancer. Lightly pigmented individuals, whether they have two or four legs are prone to it. Chewy is a cream colored Maine Coon cat who’d lived in Massachusetts for the first 7 years of his life. When he moved to Maryland, he began an outdoor lifestyle. Just as with people, sun exposure is certainly a predisposing factor with this tumor. SCC typically appears on the ear tips of white cats. It starts out looking crusty or can be a scab that won’t heal. Veterinarians can see it elsewhere on the body like the nose or the sparsely haired areas right in front of cat’s ears. In Chew’s case, his ophthalmologist saw a divot as the tumor was eating away at his lower eyelid. Animals’ coats protect them from skin cancers so it’s a bad idea to shave their coat too short in the summertime. Oddly, vets often see SCC arise from the nail bed of dogs, whatever their coat color. In that location, SCC can mimic an infection of the toe. The digit enlarges as there’s so much inflammation. A proliferative growth appears under the nail, which eventually gets loose and falls out. Squamous cell tumors are also among the three big malignancies that we see in cats’ mouths. Along with melanoma and fibrosarcoma, they carry a very poor prognosis once diagnosed.

Regardless of the location, surgery is always the treatment of choice. It’s generally a good idea to have wide margins around the tumor, ensuring that the surgeon gets all of it. In Chew’s case, Dr Weight was able to remove a pie shaped wedge of his eyelid which neither disfigured his face nor precluded his eye from shutting all the way. Radiation therapy can also be considered for areas not amenable to surgery like the nasal passages or sinuses. SCC tends to be locally aggressive, but not spread to distant sites like the lungs or liver. I am hoping that Chewy is tumor free, but I’ll be vigilant and waste no time if I see a suspicious spot. If you have a light-colored pet, be sure to do the same-and call your vet if you see an area of concern.