Treatment of subcutaneous lipomas in the horse.

Objective: To describe the treatment of subcutaneous lipomas in the horse.

Animals: 3 horses.

Clinical presentation: The horses were aged 1 to 2 years old, with lipoma of the abdomen, prepuce, and tarsus.

Results: All cases had surgical removal of the masses under general anesthesia. Recurrence of an invasive abdominal lipoma occurred in case 1 at the exit site of a passive drain. The recurrence was treated unsuccessfully with injectable cisplatin, and a second revision surgery with the use of an active drain resulted in resolution. In case 2, complete resection of an encapsulated lipoma of the lateral prepuce was successful with no recurrence. In case 3, incomplete resection of a tarsal lipoma resulted in a sound horse, with no further growth. Histopathologic analysis revealed that all masses were composed of well-differentiated adipocytes with no evidence of malignancy.

Clinical relevance: Subcutaneous lipomas are relatively rare and affect horses primarily ≤ 2 years of age. They are benign, although their presence can be deleterious due to invasion of local structures or the impact on normal locomotion. The margins of invasive tumors are difficult to identify due to their integration with normal tissue. Incomplete removal may allow for mass recurrence. Active suctions drains are beneficial if dead space is a concern.