Computed tomography and magnetic resonance imaging of maxillofacial rhabdomyosarcoma and suspected multiple metastases including the epidural space and bone marrow in a dog

A 3-year-old mixed-breed dog presenting with a recurrent maxillofacial tumor was diagnosed with recurrent rhabdomyosarcoma. Computed tomography and magnetic resonance imaging revealed a left maxillofacial mass, left cervical lymph node enlargement, epidural mass dorsal to the 6th lumbar vertebra compressing the cauda equina, soft-tissue mass ventral to the 6th lumbar vertebra, multiple subcutaneous nodules and signal changes in the paravertebral muscles. The left maxilla, lumbar spine and ilium exhibited diffuse signal changes and contrast enhancement upon magnetic resonance imaging. This is, to our knowledge, the first reported case of bone marrow and epidural-space involvement of a canine rhabdomyosarcoma.