Markers of bone remodeling in neoplastic and bone-related lesions. The aim of this study was to investigate the expression of bone resorption (RANK/RANKL), bone resorption inhibitor (osteoprotererin [OPG]), and bone formation marker (osteocalcin [OC]) in neoplastic and bone-related lesions (BRL).Using immunohistochemistry, their expression was evaluated in ossifying fibroma (OF), fibrous dysplasia (FD), simple bone cysts (SBC), central giant cell lesions (CGCL), and osteosarcoma (OS).Quantitative analyses of the expression of bone markers between all lesions, considering fibroblast-like cells and bone matrix, showed that RANK-RANKL presented higher expression in OF and CGCL, whereas OPG and OC presented higher expression in FD and SBC. There was higher expression of all proteins investigated when OS was the BRL. Moreover, the RANKL expression was greater than OPG in this neoplasm.Our data indicate that the bone resorption markers are more highly expressed in OF, CGCL, and OS than in FD and SBC, indicating a significant association between these proteins and the clinical behavior of these lesions.Copyright © 2010 Mosby, Inc. All rights reserved.