Histochemical and immunohistochemical differences between solitary oral fibroma and fibrous papule of the face

Abstract

BackgroundThe morphological similarities between fibrous papules of the face and multiple sporadic oral fibromas were mentioned long ago and a relationship between them has been reported in the literature.ObjectiveThe aim of this study was to evaluate the participation of mast cells, elastin and collagen in a series of oral fibromas and fibrous papules of the face in order to better understand the possible role of these factors in fibrosis and the formation of these lesions.MethodsThirty cases of oral fibroma involving the buccal mucosa and 30 cases of fibrous papules of the face were selected. Tissue samples were submitted to picrosirius red staining and immunohistochemistry using anti-elastin and anti-tryptase antibodies.ResultsThe percentage of tryptase-positive mast cells and expression of elastin were higher in cases of fibrous papules of the face (p < 0.05). In contrast, a higher intensity of collagen deposition was observed in oral fibromas. The results showed mast cell accumulation and higher elastin synthesis in fibrous papules of the face, and mast cell accumulation with higher collagen fiber synthesis in oral fibromas.ConclusionThese findings support the hypothesis that mast cells influence the development and growth of these lesions through different mechanisms.

Clinical and histopathological evaluation of cutaneous angiofibromas

“…The high presence of inflammatory cells in FPs may indicate the involvement of immunological cells in forming these lesions. Regarding the participation of inflammatory cells in extracellular matrix synthesis and remodeling, the main role is considered for mast cells and histiocytes 14,15 . These cells' secretion of potent mediators modulate fibrosis and angiogenesis, which are the main histopathological changes of FPs.…”

“…Regarding the participation of inflammatory cells in extracellular matrix synthesis and remodeling, the main role is considered for mast cells and histiocytes. 14,15 These cells' secretion of potent mediators modulate fibrosis and angiogenesis, which are the main histopathological changes of FPs. In our study, histiocytes were so prevalent that they were seen in more than a third of our cases.…”

The Role of Immune Cells in the Pathogenesis of Idiopathic Pulmonary Fibrosis

“…Trypsin-like enzymes are proteases secreted by mast cells and are specific to mast cells. The abnormal proliferation of mast cells that synthesize trypsin-like enzymes has been detected in many lesions associated with fibrosis, such as chronic submandibular inflammation, fibrous papules, oral fibromas [47], scar formation [48] drug-induced fiber formation [49], etc. Further, TGF-β is a major regulator of fibrosis, and mast cells are also an important source of TGF-β in focal tissues.…”

The role of inflammation in silicosis

“…Jared et al found that, unlike wild-type C57BL/6 mice, MC-deficient mice do not develop inflammation nor do they display significant collagen deposition following silica instillation ( Brown et al, 2007 ). MCs also secrete tryptase, which interacts with multiple regulatory factors, such as activating proteinase-activated receptor 2 (PAR2), inducing DNA synthesis in resting fibroblasts and promoting collagen synthesis, thereby stimulating fibroblast proliferation ( Henriques Á et al, 2016 ). Collectively, these studies highlighted a clear involvement of MCs in silicosis.…”