Primary hemangiosarcoma of the iliopsoas muscle eliciting a peripheral neuropathy

An eight-year-old, male castrated bullmastiff presented to the Kansas State University Veterinary Medical Teaching Hospital with left hind-limb paraly sis. A mass was identified in the left paralumbar soft tissue adjacent to t he fourth (L-4) to sixth (L-6) lumbar vertebrae by magnetic resonance imagi ng. The iliopsoas muscle contained the mass which was identified as a heman giosarcoma on histopathological examination.:Hemangiosarcoma is rarely repo rted as a primary tumor arising from muscle vascular: endothelium.