Giant Cells Fibroma: Immunohistochemical Study of Extracellular Matrix and Comparative Analysis With Inflammatory Fibrous Hyperplasia Using Hortega, Azan Trichrome, Congo Red and Weigert Van Gieson Methods

Abstract

The Giant Cells Fibroma is an oral lesion of unspecific clinical aspect, peculiar microscopic picture, obscure etiology and, possibly, underestimated frequency. Its extracellular matrix does not resemble those seen in other fibrous lesions, of traumatic nature, what makes its classification even more difficult. The aim of this study is to evaluate, through histochemical techniques, the extracellular matrix of 22 lesions selected at the Oral Pathology Laboratory of CESUMAR (University Center of Maringá, Paraná – Brazil), being 11 Giant Cells Fibromas and 11 Inflammatory Fibrous Hyperplasias. The methods that were used – HORTEGA, AZAN TRICHROME, CONGO RED and WEIGERT VAN GIESON – have the purpose of evidencing reticular fibers, collagenous fibers, amyloidal material and elastic fibers, respectively. The analysis of tissue slices demonstrated that presence and distribution of these components are the same in both lesions, but elastic fibers are more abundant in Giant Cells Fibroma (maybe because it lacks inflammatory mediators), corroborating for the hypothesis that the giant multinucleated fibroblasts, although different in their morphologic aspect, preserve the functional properties of mononuclear ones, seen in Inflammatory Fibrous Hyperplasias.