Clinical, Radiological and Microscopical Findings of Chondrosarcoma in a Cat

Chondrosarcoma is an uncommon malignant neoplasm in which the neoplastic cells produce chondroid and varying amounts of matrix. This tumor is the second most common primary skeletal tumor in animal. In this case, radiological and histopathological findings supported a final diagnosis of chondrosarcoma in a cat. A six-year-old male cat weighing 6.3 kg with a large and solitary mass in the right humerus was referred. The shoulder joint had a limited range of motion. Radiographs were obtained from the raised growth. The mass was surgically excised for histopathological evaluation. Microscopically, the mass was composed of bundles and nests of neoplastic mesenchymal cells. Histopathologically, multiple sized of lacunae within a homogenous cartilage matrix were observed. There was marked anisocytosis and anisokaryosis. Neoplastic chondrocytes and pleomorphic to oval cells with 1 to 3 nucleoli were seen. Based on the macroscopical, radiological and the cartilaginous differentiation of tumor cells and matrix, the mass was diagnosed well differentiated chondrosarcoma.