Lipoma in pets (dogs and cats) usually present as isolated, soft, mobile, well-defined, and circular masse. Their size can vary greatly, and it’s not uncommon for an animal to have more than one lipoma at a time. Rarely, a lipoma can become more aggressive and infiltrate surrounding tissues. Lipomas are most commonly found on the chest, abdomen, and limbs. They tend to grow slowly and usually don’t bother the animal unless poorly located or large enough to hinder movement.
Typical Characteristics of a Lipoma
- Isolated mass
- Mobile
- Well-defined
- Circular
- Soft
- Variable in size
Diagnosis of Lipoma in Pets
Since a diagnosis cannot be confirmed by visual inspection or palpation alone, diagnostic methods are essential to identify the type of cells involved and guide appropriate treatment.
The most common diagnostic method is cytology, which involves collecting cells via a fine needle and examining them under a microscope. In the case of a lipoma, the sample often appears oily, fatty, and shiny, forming droplets on the slide. Under the microscope, numerous normal, mature adipocytes are typically seen.
Another diagnostic option is histopathology (biopsy). In this test, a pathologist examines a well-circumscribed nodule composed of mature adipocytes, often surrounded by a fibrous tissue capsule.
Treatment of Lipoma in Pets
For small, well-defined lipomas, regular monitoring may be sufficient. However, if cosmetic appearance is a concern, the mass is growing rapidly, or it interferes with the pet’s comfort or mobility, surgical excision is the preferred option. Surgery is curative if the tumor is well-encapsulated and clearly defined.
What About Infiltrative Lipomas?
Infiltrative lipomas contain the same cells as typical lipomas but are not encapsulated. Instead, the adipocytes grow between muscle, tendon, and other tissue layers. These lipomas can develop in various body areas. Though rare, they are more difficult to treat.
Surgical excision remains the treatment of choice, though the success rate is lower than with standard lipomas. Recurrence is common. In severe cases, amputation of the affected limb may be necessary to maintain quality of life. Radiation therapy can also be considered post-surgery if the tumor is not completely removed.
Diagnostic methods remain the same, but CT scans or MRIs may be recommended to assess the extent of infiltration and aid in surgical planning.
