Abstract
Beta-catenin is a major protein in the Wnt signalling pathway. Although it has been studied in various types of carcinoma, little is known about its expression in mesenchymal tumours. In this study 41 specimens of a variety of mesenchymal childhood tumours were compared to 24 samples of the corresponding adult tumours to assess the diagnostic value of nuclear β-catenin expression using tissue microarray-based immunohistochemistry. Similar to adult sarcoma and fibromatosis, β-catenin was not expressed in the majority of childhood sarcomas, and its nuclear translocation was detected in paediatric fibromatosis; non-negligible levels of nuclear staining in other tumour types demonstrate Wnt pathway activation in mesenchymal neoplasms of childhood and adolescence.