Figure 6: Primary high-grade combined osteosarcoma with neoplastic chondroblasts and osteoblasts with a chondroid and osteoid matrix respectively (A). A lower magnification demonstrating the presence of both cartilage and bone areas in a lung metastasis (B). The letters in Figure B refer to the panels C-F. A well-demarcated area of neoplastic chondrocytes (C) adjacent to tumour cells forming an osteoid matrix (D) and a probable transition between chondrocytes (right side) and osteocytes (left side) were seen, (E). Another lung metastasis showed a low19 grade osteosarcoma (F). In a third lung metastasis (G), less differentiated tumour cells, but still low-grade, forming a chondroid matrix was seen (H). The morphology of this lung metastasis was similar to the kidney metastases (I). Light micrographs of dog No. 353 using objectives x 40 (A); x 1 (B); x 10 (C); x 20 (D-F); x 4 (G) and x 20 (H-I) of haematoxylin and eosin (HE) stained sections.