1. Osteosarcoma Most common primary malignancy of bone (non- hematopoietic) a malignancy of mesenchymal cells that have the ability to produce osteoid or immature bone intramedullary (majority) juxtacortical (small number) extraskeletal (rarely) origin

2. uncommon(6% to 8% of all osteosarcomas) Osteosarcomas of the jaws young children to the elderly most often in the third and fourth decades of life. (The mean age about 33 years) a slight male predominance maxilla = mandible Maxillary lesions: more commonly in the inferior portion (alveolar ridge, sinus floor, palate) > the superior aspects (zygoma, orbital rim). Mandibular tumors : more frequently in the posterior body and horizontal ramus >the ascending ramus

3. The radiographic findings vary from: 1.dense sclerosis 2.a mixed sclerotic radiolucent lesion 3.an entirely radiolucent process 1.dense sclerosis 2.a mixed sclerotic radiolucent lesion 3.an entirely radiolucent process The peripheral border ………….usually ill-defined

4. Osteogenic Sarcoma buccal and lingual expansion of the mandible. The expansion was hard and the patient complained only of pain. The clinical features are obviously non- specific.

5. pronounced clinical swelling

6. The radiograph shows remarkably little change except for a diffuse opacity in the bicuspid area

7. Here is another osteosarcoma characterized by diffuse opacity distal to the molar tooth. The patient presented complaining of pain it would certainly be easy to mistake this malignancy for an inflammatory condition involving the fully crowned tooth. The degree of opacity is dependent upon the amount of mineralized bone produced by the tumor

8. In some instances, the earliest radiographic feature represents peculiar widening of the periodontal ligament space. This 36 year-old female had slow swelling for the past four months and only minimal loosening of the involved teeth. Certainly, the pattern of bone loss is not typical for periodontal disease.

9. the typical radiographic feature of osteosarcoma as a "sun ray" effect well illustrated in this image

10. "sun ray" effect

11. Some osteosarcomas may even display a moderately well demarcated border although the lesion is predominantly radiolucent, one can identify globular opacities.

12. root resorption widening of the mesial periodontal ligament space 21 year-old female pain and swelling in the molar area diffuse opacity involving the maxillary sinus The molar teeth tested non-vital

13. The second molar was extracted and the socket appeared to be filling in nicely; however, her symptoms continued The first molar was then extracted eventually a biopsy revealed osteosarcoma are mistaken for inflammatory disease Extraction sites in malignant tumors often appear to heal rapidly because they fill quickly with proliferating malignancy

14. Histopathologic Features The essential microscopic criterion is the direct production of osteoid by malignant mesenchymal cells

15. The tumor cells : 1.relatively uniform round cells 2.spindle-shaped cells 3.highly pleomorphic cells with bizarre nuclear and cytoplasmic shapes

16. In this case, the stroma is loose but the cells are malignant and there is considerable heavily mineralized osseous tissue being formed

17. histopathologic subtypes ♦ Osteoblastic ♦ Chondroblastic ♦ Fibroblastic do not have any great bearing on the prognosis. Chondroblastic osteosarcomas........ a substantial proportion of all osteosarcomas of the jaws

18. spindling malignant fibrous stroma with formation of poorly calcified, markedly irregular bone trabeculae

19. Osteogenic Sarcoma (Chondroblastic Type)

20. Osteogenic Sarcoma Class Slide Osteoblastic

21. Osteoblastic type

22. Tumor Necrosis