Abstract
The chondrosarcoma occurred in a 10-year-old male Shepherd dog with a posterior paralysis was studied pathologically. The neoplastic tissue had developed from the 11th and 12th thoracic vertebra and extended into the spinal canal, where the neoplasm pressed and deformed the spinal cord. The tumor was egg-sized, and was covered with the perichondrium. The cut surface was bluish white and somewhat transparent and showed lobulated structure. The neoplastic tissue proliferated infiltratively into the thoracic vertebral arcus and body, besides, invaded into the spinal canal through the intervertebral foramen. The spinal cord was pressed and was deformed crescent-shaped by the invading neoplastic tissue. The neoplastic parenchyma was composed of pale homogenous matrix and polymorphic atypical chondrocytes located in various-sized lacunae. The tumor cells had a round or elliptic large pale nucleus, or double or multiple large nucleus with clumps of chromatin. The proliferation of the neoplastic tissue pushed away the peri-muscular tissue and infiltrated into the bone tissue. The tumor was probably originated from the 11th thoracic vertebral costovertebral articulation. Further, multiple spondylosis deformans might cause to give the pressure onto the costovertebral articulation and it might relate to the genesis of the tumor. The chondrosarcoma which originates from vertebra is rare, so this report is considered an interesting case.
