Infiltrative lipoma in a dog causing lysis and destruction of a thoracic vertebra without direct bony tumour infiltration

CASE REPORT An infiltrative lipoma was diagnosed and surgically treated in a female Jack Russell Terrier that had a history of progressive paraparesis and ataxia of several months' duration. Clinical signs, diagnosis and treatment of infiltrative lipoma are described. Computed tomography performed at the level of the thoracolumbar vertebral column revealed a fat density mass within the epaxial musculature expanding towards the vertebral body of T12, associated with severe bone destruction of the spinous process and dorsal lamina and invading the vertebral canal, causing dorsal compression of the spinal cord. Histopathological analysis of biopsies indicated lipoma. Surgical excision was attempted; however, en bloc removal was not possible. Histopathological investigation confirmed the diagnosis of infiltrative lipoma and failed to reveal neoplastic infiltration of the affected bone fragments, suggesting that the osteolytic process was more likely the result of mechanical compression than the result of neoplastic infiltration. Adjunctive radiation therapy was not administered. The dog recovered uneventfully and did not show signs of recurrence over a period of 36 months. CONCLUSION Surgical treatment of an infiltrative lipoma causing vertebral bone lysis, clinical signs of myelopathy had a satisfactory outcome in a dog.