Diagnostic and Biological Significance of Immunohistochemical Expression of Osteopontin and Ki67 in Fibro-osseous lesions of jaws

Abstract

Background and Aim: Fibrous dysplasia (FD) and ossifying fibroma (OF) are the most important fibro-osseous lesions (FOLs) of the jaws with similarities in radiographic and morphological features while showing completely different biological behavior. Limited studies have been evaluated immunohistochemistry markers, such as osteopontin (OPN) and osteocalcin to help differentiate these two lesions. This study aimed to assess the immunoexpression of OPN and Ki67 as potential markers for differentiation of different FOLs. Materials and Methods: This cross-sectional study was conducted on 12 FD, 19 OF, and eight FOL samples retrieved from the archives of the department of oral pathology. The specimens were examined immunohistochemically using streptavidin-biotin method for OPN and Ki67. The intensity score (IS), proportional score (PS) and total score (TS) were assessed in hard and soft tissue matrix and in mesenchymal cells for Ki67. The data were analyzed by independent samples Kruskal-Wallis. Results: Osteopontin showed positive immunoreaction in both stromal and trabecular components of all FDs and OFs. Among the scores, PS and TS of bone trabeculae were significantly different in FD and OF (P=0.005). Nevertheless, no significant difference was observed in Ki67 expression in mesenchymal cells (P=0.880) and OPN scores in soft tissue matrix between the lesions; their P-value were 0.336, 0.340 and 0.415 for IS, TS, and PS, respectively. Conclusion: Osteopontin can serve as a useful marker for differential diagnosis of FD and OF. However, we suggest evaluation of other NCMPs, especially functionally similar molecules such as bone sialoproteins (BSPs) in FOLs for differential diagnosis.

Study of Ki67 in odontogenic benign tumors

“…These data are in full agreement with studies reported in literature. 26,27 The association between the weak marking of Ki67 epithelial cells and lesions' unicolor and multilocular radiological aspects could be explained by the fact that, apart from cementoosseous dysplasia, the majority of lesions are dominated by ameloblastomas which can be multilocular or unilocular on radiography. 19,23 In addition, the association described between the weak Ki67 marking of ameloblastomas epithelial cells and cemento-osseous dysplasia could be explained by the fact that these lesions are slow-growing ones (low proliferative index) with perceptible clinical expression after several months of evolution.…”

Potential role of myofibroblasts in behavior of oral ossifying fibroma

“…Benign Fibro-osseous lesions' (BFOLs) is a generic term that includes a group of diseases affecting jaw and facial bones (Slootweg et al, 2005) which are recognized histologically by the process in which normal bone is replaced by mesenchymal tissue with proliferating fibroblast-like cells and few collagen bundles together with variable quantity of newly formed calcified tissue (Sargolzaei et al, 2017). These include: fibrous dysplasia (FD), osseous dysplasia, and ossifying fibroma (OF) and their subtypes (Slootweg et al, 2005).…”