Ezrin immunohistochemical expression in cartilaginous tumours: a useful tool for differential diagnosis between chondroblastic osteosarcoma and chondrosarcoma

Abstract

Ezrin is a cytoskeleton linker protein that is actively involved in the metastatic process of cancer cells. We have recently reported that ezrin expression in conventional osteosarcoma was an independent prognostic factor for event-free survival and overall survival. In this work, ezrin expression was found in all histological subtypes. Especially cartilaginous areas in chondroblastic osteosarcomas were immunopositive for ezrin. We wanted to know if ezrin could be a useful diagnostic marker in bone pathology. We have searched for ezrin expression in 208 cartilaginous tumours by immunohistochemistry and in 16 chondroblastic osteosarcomas. All conventional chondrosarcomas, whatever their grade, were negative, while ten of 16 chondroblastic osteosarcomas were positive. In contrast, dedifferentiated (five of 14) and mesenchymal chondrosarcomas (five of ten) showed ezrin positivity. Some chondroblastomas and more rarely chondromyxoid fibromas also exhibited ezrin expression. These data suggest that ezrin is a useful immunohistochemical marker for differential diagnosis between chondroblastic osteosarcomas and conventional chondrosarcomas with a specificity of 100%. Ezrin expression in dedifferentiated and mesenchymal chondrosarcomas which are aggressive neoplasms resistant to conventional treatment means that ezrin could be a therapeutic target. Ezrin expression in chondroblastomas is more intriguing and requires further study to assess prognostic value.

Ezrin immunohistochemical expression in chondrosarcomas, osteosarcomas and Ewing sarcoma family of tumors

“…2), and some cases of low-grade chondrosarcoma revealed poor ezrin immunoexpression; both results are in contrast with the study of Salas et al [4]. However, similar to the results obtained by Salas et al [4], the protein immunoexpression in the present series is associated with the histological grade, being higher in morphologically high-grade tumors. Highgrade osteosarcomas and chondrosarcomas stained ezrin in a higher proportion (95% and 100%, respectively, p< 0.001) than low-grade osteosarcomas and chondrosarcomas.…”

“…In conclusion, based upon present experience, ezrin IHC expression does not offer any diagnostic clues in the differential diagnosis of bone tumors since, at least, osteosarcoma, chondrosarcoma and ESFT reveal heterogeneous ezrin expression with increased expression in high-grade tumors. Ezrin cannot distinguish chondroblastic osteosarcoma from conventional chondrosarcoma as demonstrated in previous publications [4], and the histopathological study remains a crucial method for Supported This study was performed with grants from European Union (EuroBoNet project, contract no. 018814).…”

“…Dear Sir, Ezrin immunohistochemical (IHC) expression has been described in bone sarcomas, being present mainly in osteosarcomas [1][2][3][4][5]. Salas et al [4] described the utility of ezrin protein expression as a tool to differentiate between conventional chondrosarcomas and chondroblastic osteosarcomas, demonstrating a specificity of 100%.…”

“…Salas et al [4] described the utility of ezrin protein expression as a tool to differentiate between conventional chondrosarcomas and chondroblastic osteosarcomas, demonstrating a specificity of 100%. In the present study, we describe ezrin IHC expression in 397 bone tumors, including 33 osteosarcomas (eight lowgrade, 20 high-grade and five chondroblastic), 23 conventional chondrosarcomas (ten grade I, eight grade II and five grade III) and 341 Ewing sarcoma family of tumors (ESFT) [236 conventional, 42 primitive neuroectodermal tumor (PNET) and 63 atypical].…”

Phosphorylated ezrin is located in the nucleus of the osteosarcoma cell

“…These data have already been found recently in other papers, in which the authors emphasize the role of ezrin in the differential diagnosis among chondroid and osteoid tumors. 30 It is possible that ezrin may be involved in chondroid differentiation of osteosarcoma.…”