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

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

The radiographic findings

vary from:1.dense sclerosis2.a mixed sclerotic radiolucent lesion 3.an entirely radiolucent process

The peripheral border ………….usually ill-defined

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.

pronounced clinical swelling

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

Here is another osteosarcoma characterized by diffuse opacity distal to the molar tooth.

The patient presented complaining of painit 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

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.

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

"sun ray" effect

Some osteosarcomas may even display a moderately well demarcated border

although the lesion is predominantly radiolucent, one can identify globular opacities.

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

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

Histopathologic Features

The essential microscopic criterion is the direct production of osteoid by malignant mesenchymal cells

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

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

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

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

Osteogenic Sarcoma (Chondroblastic Type)

Osteogenic SarcomaClass Slide Osteoblastic

Osteoblastic type

Tumor Necrosis