Cat Lipomas

What Is a Cat Lipoma?

Lipomas are classically known as the “fatty tumor” of the animal world, and there is much truth to this nickname.

They arise from fat cells and are benign, slow-growing, noncancerous tumors.

While lipomas are common in dogs, they are encountered far less frequently in cats. When they are seen in cats, the patient is typically middle-aged or older.

Symptoms of Cat Lipomas

Although only one mass may be present, cats that do develop lipomas will often develop more than one.

The lesion is most likely found on a cat’s chest, abdomen, neck, back, and upper legs, though no location is off limits. They are found most often in the subcutaneous tissues beneath the skin, though they can grow on internal organs as well.

To the touch, lipomas in cats are most often soft and somewhat moveable, but they can also be firmer and more adhered to the nearby tissues.

They should be the same temperature as the nearby skin, and the skin above them should appear normal and without lesions.

When they grow quite large, which happens less in cats than dogs, they can outgrow their blood supply and become necrotic (tissue death).

Causes of Cat Lipomas

We don’t fully understand why cats get lipomas, and why dogs get so many more than cats.

Obese and overweight cats are more likely to develop lipomas than those with healthy body conditions.

How Vets Diagnose Cat Lipomas

Any new or changing mass on a cat should always be evaluated by your veterinarian, and a suspected lipoma is no different.

Your veterinarian will likely recommend a test called a fine-needle aspirate (FNA) and cytology. Most veterinarians will perform this test in-house, though it may be sent out to a reference laboratory.

For this test, the veterinarian inserts a needle into part of the mass to obtain a sampling of cells. The cells are “smeared” onto a microscope slide, stained, and prepared for microscopic examination.

Lipomas are often easily diagnosed by classic appearance under the microscope. For a confirmative diagnosis, a larger tissue simple called a biopsy is necessary. This is a slightly more invasive procedure requiring a brief surgery, though it’s still extremely safe.

Treatment for Cat Lipomas

Most lipomas only require monitoring. There is usually no reason for treatment of cat lipomas, as they pose no threat unless they are uncomfortable due to large size or an awkward location.

The growth of most lipomas is quite slow, which gives you time before making a hasty decision to have a lipoma surgically removed if you are on the fence.

Lipomas that are larger, fast-growing, or invasive into surrounding tissue may be appropriate candidates for surgical removal. Invasive lipomas make surgical removal more challenging, and they are likely to recur.

It is important to have an accurate diagnosis so you know that the mass is indeed a lipoma and not a malignant liposarcoma, as their treatments are radically different.

Recovery and Management of Cat Lipomas

Overall, the prognosis after a diagnosis of a cat lipoma is generally good and not a cause for alarm.

If you make the choice for a conservative approach—with the approval of your veterinarian—closely monitor the size and growth rate of your cat’s lipoma on a regular basis.

Record this information every three months. Documenting any changes in shape, firmness, or skin lesions is also important. Changes can indicate a need to reevaluate the mass with a biopsy.