1. Peripheral giant cell granuloma ( PGCG ) a relatively common tumorlike growth of the oral cavity. a reactive lesion caused by local irritation or trauma. Some investigators ….. 1.the giant cells show IHC features of osteoclasts 2.mononuclear phagocyte system. a close microscopic resemblance to CGCG some pathologists …….a soft tissue counterpart of this central bony lesion. Peripheral & central giant cell granuloma

2. The clinical appearance is similar to the more common pyogenic granuloma of the gingiva. Peripheral giant cell granuloma. pyogenic granuloma Most lesions <2 cm in diameter although larger ones are seen occasionally. sessile or pedunculated may or may not be ulcerated. Exclusively on the gingiva or edentulous alveolar ridge a red or reddish-blue nodular mass Often is more bluish-purple compared with the bright red of a typical pyogenic granuloma peak prevalence …… fifth and sixth 60% in females anterior or posterior Mandible is affected slightly more often than the maxilla

3. Histopathologic Features a proliferation of multinucleated giant cells within a background of plump ovoid and spindle-shaped mesenchymal cells

4. Copyright © 2003, Elsevier Science (USA). All rights reserved. hemorrhage is characteristically found throughout the mass ………… deposits of hemosiderin pigment, especially at the periphery of the lesion. only a few nuclei or up to several dozen

5. The overlying mucosal surface is ulcerated in about 50% of cases. Adjacent acute and chronic inflammatorym cells are frequently present A zone of dense fibrous connective tissue usually separates the giant cell proliferation from the mucosal surface

6. Areas of reactive bone formation or dystrophic calcifications are not unusual

7. CENTRAL GIANT CELL GRANULOM A a non neoplastic lesion Some lesions ….aggressive ……similar to that of a neoplasm. 2 to 80 yrs 60% before age 30 a majority in females 70% mandible anterior portions of the jaws cross the midline Most giant cell granulomas are single lesions

8. 1.Non aggressive lesions: no symptoms slow growth no cortical perforation or root resorption 2.Aggressive lesions : pain, rapid growth cortical perforation root resorption. a marked tendency to recur after treatment Based on the clinical and radiographic features:

9. Radiographically Size:vary from a 5 X 5 mm ………..to a destructive lesion greater than 10 cm A unilocular or multilocular radiolucent defect usually well delineated, but generally noncorticated

10. The radiographic findings are not specifically diagnostic Small unilocular lesions may be confused with periapical granulomas or cysts.

11. Multilocular giant cell lesions cannot be distinguished radiographically from ameloblastomas or other multilocular lesions.

12. Histopathologic Features the presence of few to many multinucleated giant cells in a background of ovoid to spindle shaped mesenchymal cells. There is evidence that these giant cells represent osteoclasts The giant cells may be aggregated focally in the lesional tissue or may be present diffusely throughout the lesion

13. These cells vary considerably in size and shape from case to case

14. In some cases, the stroma is loosely arranged and edematous

15. in other cases, it may be quite cellular

16. Areas of erythrocyte extravasation and hemosiderin deposition often are prominent Older lesions may show considerable fibrosis of the stroma Foci of osteoid and newly formed bone are occasionally present within the lesion.

17. large giant cells uniformly distributed giant cells a predominantly cellular stroma clinically aggressive with a greater tendency to recur after surgical treatment Correlation of the histopathologic features with clinical behavior remains debatable