Invasion of Hemangiosarcoma from Lung to the Spinal Cord in a Dog

11-year-old neutered male dog was presented with paralysis with decreased postural reaction in the bilateral pelvic limbs. On MRI and CT, the spinal cord from T13 had a slightly swollen area and lost the central canal. A well circumscribed mass was observed at anterior of a right kidney and invaded the spinal canal through the pleura without the fusion and destruction of the spines. Hemilaminectomy was performed to identify the mass pathohistologically and decompress the spinal cord. The mass was diagnosed as hemangiosarcoma. The dog had showed neither progressive neurologic disorders nor improvement and passed away 58 days after the surgery.