Aims The field of molecular pathology has undergone significant advancements in the clinical impact of sarcoma diagnosis, resulting in challenges to nosology of bone and soft tissue tumours. The surge in molecular data has led to the identification of novel fusions and description of new ‘entities’. To illustrate this, we have selected five emerging entities with novel fusions: clear cell stromal tumour of the lung with YAP1::TFE3 fusion, GAB1::ABL1 fusion spindle cell neoplasm, NUTM1 -rearranged sarcomas, NR1D1 -rearranged sarcomas and calcified chondroid mesenchymal neoplasms. Methods Literature for the relevant case reports and case series of these five entities were reviewed and clinicopathological data was collected. Additionally, this review includes a table format of recently described fusion-associated mesenchymal neoplasms. Results The morphological and immunohistochemical features, along with diagnostic challenges, are discussed for each entity. Conclusions Here, we have prov

Aims Mutations affecting exon 3 of the β-catenin ( CTNNB1 ) gene result in constitutive activation of WNT signalling and are a diagnostic hallmark of several tumour entities including desmoid-type fibromatosis. They also define clinically relevant tumour subtypes within certain entities, such as endometrioid carcinoma. In diagnostics, β-catenin immunohistochemistry is widely used as a surrogate for CTNNB1 mutations. Yet, it is often difficult to assess in practice, given that the characteristic nuclear translocation may be focal or hard to distinguish from the spillover of the normal membranous staining. Methods We therefore examined lymphoid enhancer-binding factor 1 (LEF1) immunostaining, a nuclear marker of WNT activation that serves as a potential surrogate for CTNNB1 mutations. Results In a cohort of endometrial carcinomas with known mutation status (n=130) LEF1 was 85% accurate in predicting CTNNB1 mutation status (64% sensitivity, 90% specificity) while β-catenin was 76% accurat

Aims During detailed analysis of H&E-stained histological slides of 710 unbiased conventional renal cell carcinomas (cRCCs), 141 tumours displayed partial regressive changes showing strong similarity to that of wound healing. We aimed to analyse the molecular processes occurring in regressive tumours. Methods Immunohistochemistry was applied to analyse the signalling molecules in 12 selected tumours, and statistical analysis was used to estimate the correlation between regression and the outcome of the disease. Results The regressive areas displayed inflammatory granulation tissue expressing transforming growth factor beta-1 (TGFB1), interleukin-1 beta and interleukin-6 (IL1B and IL6), proliferation of alpha smooth muscle actin (αSMA) positive naïve activated fibroblasts and a diffuse fibronectin 1 (FN1) network. In the central areas of regressive tissues, parallel-running myofibroblasts showed FN1, collagen type I alpha 1 (COL1A1) and collagen type III alpha 1 (COL3A1) positive immuno

In collaboration with the Association of Clinical Pathologists, JCP is pleased to launch the ACP-JCP Early Career Prize for Best Original Research Paper. The annual prize will recognise an outstanding contribution to the journal from an early career individual. The recipient of the award shall be granted a prize certificate and a monetary award of £500. The first prize will be awarded in 2025. Papers published online in JCP in 2024 will be considered. To be considered for the award, the recipient and