Lumbar epidural chondrosarcoma in a dog treated by excision and chemotherapy.

: A 5-year-old dog developed neurologic signs of thoracolumbar spinal cord dysfunction. The presence of an epidural mass which affected the electromyogram of the T-13 to L-3 spinal segments was demonstrated by myelography. Surgical removal was attempted. Examination of frozen and formalin-fixed tissues revealed the mass to be a chondrosarcoma. Doxorubicin hydrochloride was given every third week for a total of 6 doses following surgery. No signs of recurrence or metastases have been found for over 6 months. The differential diagnosis of epidural masses should include chondrosarcoma, even in the absence of vertebral lesions on plain radiographs, as in this case. Rapid diagnosis and aggressive therapy may have improved the prognosis.