Abstract
Synovial sarcoma was found in a five-year-old male Yorkshire Terrier. The dog suffered from lameness of unknown cause in the right hind limb for about 6 months with subsequent hard swelling of the thigh. On radiographs, a clearly demarcated, localized destructive lesion was noticed in the caudomedial part of the supracondyloid region without any finding suggestive of aggressiveness or periosteal osteogenesis. A jelly-like substance was collected by biopsy from the deep femoral region close to the destructive supracondyloid lesion. Histologically, it was characteristic of synovial sarcoma.
Euthanasia and necropsy were performed 41 days after it was admitted to the hospital for the first time due to progressive deterioration of clinical manifes tations which had not been improved by administration of a nitrosourea derivative.
