Pituitary Tumors In Cats

The pituitary gland is a hormone-producing gland located at the base of a cat’s brain. Because the hormones that are produced there control many body functions, pituitary health is important. There are different issues that can impact the pituitary gland, but pituitary tumors are extremely rare in cats. Fewer than 1% of cats develop a pituitary tumor, and it’s even more rare for a pituitary tumor to be malignant (cancerous). However, even a benign tumor can impact a cat’s well-being due to the growth of the tumor. Signs are often neurological — a cat may have difficulty walking, for instance — and a tumor also can lead to diabetes or blindness. Fortunately, many cats respond well to radiation, and there are cases where symptoms are completely resolved over time.

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Types Of Pituitary Tumors In Cats

Cats that develop these rare tumors tend to be at least 10 years old. There is no particular predilection regarding breed or sex of the cat.

Adenoma: The most common type of pituitary tumor is called an adenoma. They are benign, which means they aren’t cancerous and won’t metastasize (spread), but they will continue to grow locally. Larger tumors are called macroadenomas; smaller ones are microadenomas. Because of its size and location, a pituitary macroadenoma in cats can impact brain function.

Adenocarcinoma: A pituitary tumor that is malignant is an adenocarcinoma. These are very, very rare. Malignant cells can spread, including to the liver, lungs and lymph nodes.

Clinical Signs To Look For

Not only can pituitary tumors impact hormone production, but as they grow, they can press on the optic nerves and parts of the brain. Pituitary tumors thus can result in a wide array of symptoms:

  • Neurological — A cat with a pituitary tumor can experience ataxia, a loss of control of its body movements. The cat may continuously circle in one direction or demonstrate other difficulty walking. He or she also may experience weakness and be lethargic or appear to be mentally dull.
  • Feline acromegaly Pituitary tumors can cause physical changes in cats, such as an enlarged forehead or protruding jawbone. Excessive secretion of growth hormones — which are regulated by the pituitary gland — is the cause of acromegaly in cats.
  • Blindness — A cat can experience vision loss when a pituitary tumor presses on optic nerves. Depending on the treatment course and response, the blindness might be temporary. As an aside, many cats actually do well blind as long as their owners don’t move the furniture around.
  • Endocrine related — Because the pituitary gland is part of the endocrine system, a tumor can also affect other hormones, including insulin, which helps regulate blood sugar levels. A cat thus may have diabetes that cannot be regulated well. The cat may drink or urinate with increasing frequency, may experience weight loss and may be ravenous because its body is not converting food into energy. It’s noteworthy, however, that being diabetic does not necessarily imply that your cat has a pituitary tumor.

Diagnosing Pituitary Tumors

The procedures a veterinarian uses to diagnose a pituitary tumor may vary based on the specific signs the cat is exhibiting:

  • Bloodwork, urinalysis and checking blood glucose levels are typical.
  • If malignancy is a concern, chest X-rays and/or an abdominal ultrasound may be performed to determine whether malignant cells have spread to the lungs or elsewhere.
  • AN MRI of the brain will help determine the size and exact location of a tumor.

Treatment Options & Prognosis For Pituitary Tumors

Radiation is the most common treatment for a feline pituitary tumor. It is designed to shrink the size of the mass. Within weeks to a few months after radiation is complete, some signs could be completely resolved. A cat that went blind can get its vision back. Diabetes might be easier to regulate, and the cat might not need insulin at all. The “circling” and difficulty walking can improve, although a cat might still seem a little “off” due to scar tissue. Cats do well after radiation for one to two-plus years.

There are two primary types of radiation:

Conventional Radiation

With conventionally fractionated radiation therapy (CFRT), a cat typically will undergo 16 to 18 treatments.

Stereotactic Radiation (SRS/SRT)

Stereotactic Radiation is an innovative treatment available for cats with pituitary tumors. It usually requires just one to three treatments. The radiation plan typically targets less than 1 mm of tissue, damaging the tumor while leaving surrounding healthy tissues out of the radiation field as much as possible. The lower number of treatments also means a cat is not subjected to anesthesia as frequently. The PetCure Oncology team is highly qualified to provide stereotactic radiation therapy.

Managing Symptoms

Radiation may not always be feasible due to a cat’s condition or a pet owner’s circumstances. If that’s the case, steroids can be used to manage neurologic symptoms and improve quality of life. Steroids, however, could make managing diabetes more challenging.  In the absence of any treatment, a pituitary tumor will continue to grow. Existing signs can worsen and other signs can develop. The cat may eventually just not feel well, lose its appetite and continue to lose weight. Decisions then must be based on quality-of-life issues.

Find A PetCure Oncology Location Near You

While pituitary tumors are rare, you will want to provide the best care possible if your cat is diagnosed with one. PetCure Oncology understands what you are going through, and it’s our mission to provide the most advanced and innovative treatment options available. We support you and your cat through our clinical excellence, professionalism, compassionate care and treatment options with the goal of prolonging your cat’s life — and quality of life — as long as possible.

To learn more about PetCure Oncology and our innovative treatment options, find a location near you today.

Types of Cancers In Cats

If your pet is displaying any symptoms of cancer or has been diagnosed with cancer, sort below by cancer type or tumor location to learn more about each cancer type and available treatment options for your pet. Click on the links for more specific information on treatment and real patient stories.




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