giant-cell fibroma giant-cell fibroma giant-cell fibroma is a type of fibroma not associated with trauma or irritation. it can occur at any age and on a mucous membrane surface. the most common oral locations are on the gingiva of the mandible, tongue, and palate. it is a localized reactive proliferation of fibrous connective tissue. giant-cell fibroma (gcf) is a benign non-neoplastic lesion first described by weathers and callihan (1974). it occurs in the first three decades of life and predominates in females (houston, 1982; bakos, 1992). clinically, the gcf presents as an asymptomatic, papillary and pedunculated lesion. the most predominant location is the mandibular gingiva (houston, 1982; bakos, 1992). histologically, the gcf is distinctive, consisting of fibrous connective tissue without inflammation and covered with stratified squamous hyperplastic epithelium. the most characteristic histological feature is the presence of large spindle-shaped and stellate-shaped mononuclear cells and multinucleated cells. these cells occur in a variety of lesions, such as the fibrous papule of the nose, ungual fibroma, acral fibrokeratoma, acral angiofibroma and desmoplastic fibroblastoma (swan, 1988; pitt et al., 1993; karabela-bouropoulou et al., 1999; jang et al., 1999). despite many studies, the nature of the stellated multinucleate and mononuclear cell is not clear (weathers and campbell, 1974; regezi et al., 1987; odell et al., 1994; magnusson and rasmusson, 1995). diagnosis pcna and ki67 immunoreactivity happens in case of fibroma and peripheral granuloma.