A Large Intermuscular Lipoma in the Axillary Region of a Dog: Diagnosis, Surgery and Follow-up

Lipoma is considered a benign tumor of adipose tissue that typically develops in subcutaneous tissue. While this type of tumor is common in older and obese dogs, intermuscular lipomas are rare in veterinary medicine. This report represents the clinical signs, physical examination, and diagnostic imaging findings of intermuscular lipoma in the axillary region of a 12-year-old intact male mixed terrier dog. Diagnostic tests, including ultrasonography, computed tomography (CT) and fine-needle aspiration, were performed. The mass was removed entirely using blunt dissection with a safe margin under general anesthesia. A large fatty tumor between the deep pectoralis and superficial pectoralis muscles was found during surgery. Macroscopic and microscopic examinations revealed a non-encapsulated mass with a soft, greasy consistency, containing differentiated and benign adipocytes, indicating lipoma. During the examination six months after surgery, the patient showed no lameness and other neurological complications, and there were no signs of mass recurrence. Intermuscular lipomas are rarer than other types of lipomas. Complete surgical excision is the optimal treatment for intermuscular lipomas, yielding an excellent prognosis post-surgery.