peripheral giant cell granuloma, A relatively common oral tumorlike growth consisting of multinucleated giant cells. The cells resemble osteoclasts; some researchers believe the granuloma is a formation of mononuclear phagocytes. The lesion can be sessile or pedunculated and can develop at any age; it is caused by local irritation or trauma but is not thought to be a reparative reaction for the body. A similar lesion located within bone is called a central giant-cell granuloma. Compare peripheral ossifying fibroma, cementifying fibroma.