Samantha is a 12 year old, spayed female Pembroke Welsh Corgi who presented after the owner noticed she was getting a little fat. Samantha’s case was unusual because she was eating and drinking and relatively acting normal. Samantha’s radiograph’s revealed that she was actually not gaining weight but rather her spleen had become very enlarged. Ultrasound confirmed that her spleen was in fact enlarged and that there was a large growth on one side. Her blood work, which included a complete blood count, chemistry and coagulation profile were all normal. Having an enlarged spleen is dangerous not only because the cause of enlargement could be a very aggressive cancer but also because it is very fragile and can rupture easily.
Samantha’s amazing owner took the chance and underwent surgery not knowing if she had a cancerous or non cancerous spleen enlargement. Samantha’s spleen was removed during a surgical procedure called a “splenectomy.” She awoke from anesthesia without complication. She recovered amazingly and had her sutures taken out 10 days later. The spleen was sent for testing called histopathology and came back as benign hyperplasia.
Samantha and her wonderful owner have many more happy times ahead. Meadowlands Veterinary Hospital was happy to help them through this emotional journey.
What is a spleen?
- An abdominal organ that’s main function is to filter blood, remove worn out blood cells, and recycle proteins and iron. It is also a reserve factory for blood cells, like a natural transfusion. Its secondary function is to the immune system. It can recognize “foreign” materials like infectious microorganisms, help destroy them and then provide immunity in the future.
What type of tumors form in the spleen?
- Tumors of the spleen are common in older dogs, but rare in cats. Most enlargements of the spleen are not cancerous. In some cases, the enlargement may be due to blood accumulation, called a hematoma or tissue overgrowth called hyperplasia. Less commonly, the enlargement is due to infection or inflammation called splenitis.
- Cancers of the blood vessels are also common such as hemangioma (benign) and hemangiosarcoma (malignant). Lymphoma, lymphosarcoma, mast cells (mastocytoma), or other white blood cells cancers like leukemia may involve the spleen.
Who gets them?
- Tumors are common in the spleens of older dogs but rare in cats.
- German Shepherds have a higher incidence of hemangiosarcoma.
- Boxers have a higher incidence than other breeds of lymphoid cancer involving the spleen.
- Bernese Mountain Dog’s have a high incident of malignant histiocytosis
- In cats, lymphoid cancer is the most common cancer making up approximately 1/3 of all cancer cases.
- Any large breed dog appears to be at an increased risk especially Golden Retrievers, Labradors, and Poodle.
What are the signs?
- Swelling of the abdomen, vomiting and loss of appetite. Other signs may include lethargy, fever, weight loss, petechial (pinpoint) hemorrhage, anemia, diarrhea and increased urination. Rapid growth of the tumor may make the spleen rupture spontaneously, with acute collapse and breathing difficulty leading to death.
- With lymphoid tumors in dogs, there is usually generalized symmetrical swelling of the lymph nodes
- Most cats with splenic tumors will show symptoms of a swollen abdomen, weight loss, diarrhea or constipation and vomiting. Kidney failure and anemia are also common.
How are these cancers diagnosed?
- X-rays and ultrasound are often helpful to detect tumors, but cannot always distinguish between hyperplasia and true cancer.
- Exploratory surgery to obtain tissue samples is the most reliable method
- Cytology, the microscopic examination of cell samples, is not reliable
What types of treatment are available?
- Surgical removal of the whole spleen is the treatment of choice.
- Benign tumors will only affect the spleen but most malignant cancers have already spread before diagnosis and surgery. Removal of the spleen does not cure the disease although it slows the progress.
- Chemotherapy rarely cures the disease. Significant remission is more likely for smaller and more rapidly dividing tumors.
- Steroid drugs such as prednisolone will give short-term palliation for up to a few months.