Thymoma in Cats
The thymus is a small glandular organ located in front of the heart. Its special function is to serve as a reservoir for the production and maturation of T lymphocytes, white blood cells that make up an important part of the body's immune system. A thymoma is a tumor originating from the epithelium of the thymus (the layer of tissue covering the thymus). Thymomas are rare tumors in cats and are mainly associated with myasthenia gravis, a severe autoimmune disease which causes certain muscle groups to tire easily.
Symptoms and Types
- Increased breathing rate
- Trouble breathing
- Cranial caval syndrome -- a side effect of heartworm infestation, which often leads to swelling of the head, neck, or forelimbs
- Myasthenia gravis, a neuromuscular disease that leads to muscle weakness, enlarged esophagus, and frequent regurgitation
Your veterinarian will perform a thorough physical exam on your pet, taking into account the background history of symptoms and possible incidents that might have led to this condition. A complete blood profile will be conducted, including a chemical blood profile, a complete blood count, a urinalysis, and an electrolyte panel.
Thoracic X-rays are standard for breathing related conditions. The resulting images may show a cranial mediastinal mass (a mass between the lungs), pleural effusion (build-up of fluid in the lungs due to aspiration pneumonia) and megaesophagus.
A blood test for antibodies to acetylcholine receptors (a neurotransmitter causing muscles to contract) should be performed to rule out myasthenia gravis. A tensilon test can also be used to test for myasthenia gravis.
A fine-needle aspirate of the mass will show mature lymphocytes (white blood cells) and epithelial cells (cells forming in the outside layer of the thymus gland).
Patients should be hospitalized in preparation for surgery to remove the thymoma. These types of tumors are highly invasive and sometimes difficult to remove. Twenty to thirty percent of thymomas are found to be malignant, with metastasis (spread) throughout the chest and/or abdomen.
Living and Management
If the tumor is completely surgically resectable (and has not spread), full remission is generally assured. Your veterinarian will schedule follow-up appointments every three months with you to retake thoracic X-rays of your cat in case the tumor should recur.
The disappearance of the signs and symptoms of a particular disease; this is often used in association with cancer
The return of food into the oral cavity after it has been swallowed
Any sub stance that allows impulses to be transmitted from one neuron to the next
Pertaining to the chest
A neoplasm that occurs as related to the thymus
An in-depth examination of the properties of urine; used to determine the presence or absence of illness
A gland found near the midline of the chest cavity; found mostly in young animals
The area found between the muscles and the endings of the nerves
A covering of cells that turns into the outermost layer of skin and covers the body
The escape of fluid or blood into tissues or body spaces or cavities
Any disease in which an animal's body creates antibodies that are used against itself.
The tube that extends from the mouth to the stomach
Something that becomes worse or life threatening as it spreads
a) inhaling b) getting out fluid or gas by the act of sucking.
The term for an esophagus that is enlarged abnormally
The term for weakness of the muscles