Lymphoma is a cancer arising from the lymphocyte, which is one of the body’s white cells involved in the immune system. Lymphocytes are normally present throughout the body in all the tissues. They circulate in the blood stream as well as the lymphatic system.

Lymphocytes are rapidly reproducing cells, which give them the ability to increase their numbers when there is a threat to the body. Because they reproduce so frequently, they are more likely to develop mutations, which can lead to the development of cancer.

When lymphocytes become cancerous the severity of their transformation can vary to mildly cancerous (where the cancerous cells resemble the original cells and don’t do too much damage) to severely malignant where the cells do not resemble the original cells at all. When the cancerous cells are “small cell” they are one of the more mild forms of this cancer. Fortunately, cats with this type of cancer tend to respond well to drug therapy.

What are the symptoms of small cell lymphoma?

The symptoms that occur with small cell lymphoma vary with the organ system that is affected. Since the lymphocytes are present in virtually all the body’s organs, the cancer can strike anywhere. The most common form of this cancer affects the gastrointestinal tract. When this occurs the following signs are present:

  • Lack of appetite
  • Weight Loss
  • Vomiting
  • Diarrhea

How does our veterinary team make the diagnosis of Small Cell Lymphoma?

There are many other diseases that present with similar symptoms so we must run a battery of tests to diagnose this disease. These tests generally include:

  • Blood Tests
  • Urine tests
  • Radiographs of the chest and belly
  • Ultrasound of the abdomen

These tests will help us rule out other causes of the disease. Ultimately, our veterinarians must obtain biopsies of the affected organs to make a definitive diagnosis of this disease. This generally requires exploratory surgery during which the entire abdomen can be inspected and multiple tissue samples can be obtained for laboratory analysis. It is not uncommon for multiple organs to be affected by this disease due to the wide distribution of the lymphocyte in the body.

How does our veterinary team treat Small Cell Lymphoma?

Small cell lymphoma is one of the most treatable cancers in the cat. Most cats can achieve remission (not cure) from the disease with the aid of drug therapy In most cases this will involve the use of prednisone and chlorambucil which are potent anti-cancer drugs. Sometimes more aggressive therapy with multiple drugs may be warranted depending on the grading of the cancer based on biopsy.

Vitamin supplementation by injection may be warranted and special hypoallergenic food may be helpful.

Most cats tolerate these drugs well but there may be side effects associated with them. In particular, depression of the bone marrow is a serious side effect, which can occur. As a result, our veterinarians must monitor the blood on these patients on a regular basis.

What is the prognosis?

Cats vary in how quickly they respond to therapy. Some may improve within days of initiating therapy, but some cats may take up to 3-4 weeks to fully respond to the therapy. Ultimately most of them will respond. Once they do, the symptoms will reduce significantly or even go away. Some cats may require more aggressive therapy if the initial therapy fails to resolve the symptoms. Many cats can live for a number of years with this disease providing appropriate monitoring and therapy are maintained.