Feline Thymoma

Thymoma is a type of cancer which results in a tumor on the thymus gland. Your thymus gland is located underneath the breastbone near your lungs and it helps to regulate your immune system. Thymoma can affect humans as well as animals like cats. However, according to the Veterinary Society of Surgical Oncology (VSSO), feline thymoma is rare. Thymoma in cats is also treatable when caught early.

  1. Types

    • There are two types of feline thymoma: invasive and non-invasive. Invasive thymoma can cause the tumors on the thymus gland to spread to other organs, such as the lungs. A tumor that does not metastasize indicates non-invasive thymoma. The VSSO reports that at least 50 percent of feline thymoma cases are non-invasive. A biopsy of the thymus gland is performed and tested to determine whether the tumor is invasive or not.

    Symptoms

    • According to the U.S. National Library of Medicine, the most common symptom in feline thymoma is breathing difficulties. These can be characterized by coughing, wheezing, and choking. Other symptoms may include weight loss and an inability to walk. The International Veterinary Information Service (IVIS) explains that dermatitis can develop on the skin located above the thymus tumor. These skin rashes can eventually spread to the neck and hands. Symptoms of invasive and non-invasive feline thymoma do not differ.

    Treatment

    • Treatment for feline thymoma includes radiation therapy, chemotherapy or surgery. According to the VSSO, radiation therapy is preferred for non-invasive tumors in a cat and has a 75 percent success rate. Chemotherapy for invasive feline thymus is only effective when used in conjunction with a corticosteroid. Your veterinarian will recommend surgery as a last resort. An invasive tumor on the thymus gland often requires surgical removal in order to prevent metastasis.

    Outcome

    • The VSSO reports that cats that have thymoma have a high chance of survival once the cancer is caught early. However, skin rashes on your cat may be more difficult to treat as they are more likely to spread to other areas. Since dermatitis from thymoma is a cat's response to immune system changes, your cat's skin should improve once thymoma treatment is complete.

    Considerations

    • The exact cause of feline thymoma is unknown. However, gender and age can play a role in the development of thymoma in cats. The VSSO reports that male cats have a higher chance of developing thymus tumors. Also, the median age of feline thymoma development is 10.8. If your cat experiences any symptoms of thymus, call your veterinarian immediately. Even though invasive feline thymoma is rare, complications may arise in other organs.