Lipoma in Cats
Lipomas are soft masses or tumors that lie beneath the surface of the skin. They are usually palpable, with limited mobility under the skin. The overlying skin is usually not affected. Over time they can grow larger and can impede movement if they are located between the legs or low on the chest. It is important to recognize that additional masses do not necessarily indicate malignancy or metastasis. Because other cutaneous masses may appear similar to lipomas, it is recommended that each mass be checked.
Another sub-classification of benign lipomas is the infiltrative lipoma. These typically invade locally into muscle tissue and fascia and may need to be removed.
Conversely, liposarcomas are malignant and can spread (metastasize) to the bone, lungs, and other organs. These tumors are rare, but are demonstrative of the need to examine each subcutaneous mass individually.
Symptoms and Types
Most lipomas feel soft and movable under the skin. They usually will not cause discomfort unless they are in a location where normal movement is disrupted, like in the axillary region under the front leg. Often they are located on a cat's belly or trunk, but can be found anywhere on the body.
Your veterinarian will perform a complete physical on your cat, checking for all palpable masses. A fine needle aspirate of the mass will indicate whether it is in fact a benign lipoma. Diagnosis of this is essential, as other more worrisome masses can mimic a lipoma. If the aspirate is inconclusive, surgical removal and a histopathology may be necessary to arrive at a clear diagnosis.
Infiltrative lipomas may require computed tomography (CT) or magnetic resonance imaging (MRI) to adequately understand the mass and its location in the tissue. This is important information for the surgeon to decide how much of the mass can or should be removed and the approach that will be needed for surgery.