Welcome to March's Case of the Month! This month we'll look at a cat with a runny nose that was more than just a runny nose.

THE NOSE KNOWS

HISTORY

Mercury was a 6-year-old cat who came to us because he had been having discharge from his nose for about a month. Sometimes he'd sneeze, sometimes he'd have some discharge, but his attitude otherwise seemed fine. However, he did seem to have lost his appetite, and would walk over and sniff his food, then walk away as if he couldn't smell it.

PHYSICAL FINDINGS

Mercury's examination revealed some thick yellow discharge from his left nostril. He did not appear painful, and no swelling was visible. His temperature was normal. Because his problems started about the same time he got a new catnip toy, we were concerned that he may have inhaled a piece of catnip that got itself stuck up his nose. The discharge suggested infection, which could have been a sinus infection or could have been the result of something in his nose. His owner agreed to treat the infection first, and he was prescribed antibiotics for a week.

Unfortunately, when we took a look at Mercury after his antibiotics, he was no better. We needed to evaluate his nose and sinuses more fully, so we took some x-rays.

X-RAY RESULTS

A little information will help you understand this x-ray better. This is a view with Mercury lying on his back. His nose is to your left, his body to your right. When you put your mouse over the "what's he talking about?" you'll see a few things: "K9" will appear over his canine teeth ("fangs"); open circles will appear where his eye sockets are; a thin line will show the division between the left and right halves of his nose; finally, a splotch on the lower left side of the x-ray shows a lack of bone definition. Take a look:

What concerned us was the loss of bone definition inside the left half of his nostril. If you look closely on the right side, normal bone and cartilage inside the nostril is visible as faint white or grey lines. On the left side, little is visible of this material. What this suggested was that something was causing destruction of the bone inside of his nostril. Infections could cause this; so could cancer. To get a better idea of what was happening, we looked up into his nose with an endoscope. (By the way, he was asleep the whole time. Good x-rays of the skull require anesthesia for proper positioning.) Here's what we saw:

There was a tumor growing inside of his nose. It was blocking a good deal of his left nostril, and the surface had become infected. In the picture above, the reddish-pink color on the right and left is normal tissue in Mercury's nostril. The whitish lump in the center is the tumor, with some pus and mucus stuck to it. Here's another view, with some of the gunk cleaned off (the reddish areas are some bleeding from us taking a biopsy sample):

The biopsy sample showed the growth to be a lymphoma, a malignant form of cancer.

TREATMENT

Unfortunately, the type and location of the tumor meant that we probably wouldn't be able to remove all of it surgically. Mercury's parents didn't want to make him go through such a major procedure, and didn't want to put him through chemotherapy, but wanted to try something. The next best option was to remove as much of the tumor as we could endoscopically, then add something medically to try and minimize its growth afterwards.

In a procedure a week after the x-rays, we were able to remove about 80% of the tumor using the endoscope. We then started Mercury on prednisone, which is part of the chemotherapy treatment for lymphoma, but has minimal side effects if used carefully. So far, he's doing well, sneezing occasionally, but the discharge is gone. He also seems to have regained his sense of smell, and his appetite is back to normal.

DISCUSSION

Lymphoma is one of the most common cancers of cats. It frequently appears in the intestines or within the chest cavity, but less commonly appears as a solid growth elsewhere. It can also be associated with feline leukemia. Unfortunately, the best hope in treatment is remission rather than a cure.

We'll have another case next month. And I promise, no more cancer for a while!

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