Yoshida A, Arai Y, Hama N, et al. - Four men and three women ranging from 26 to 71 years in age with BCOR-associated non-uterine sarcomas were studied. Three tumors, two of which principally impacted the kidney, exhibited BCOR-CCNB3. One tumor with a ZC3H7B-BCOR and a tumor with a novel CIITA-BCOR transpired in the chest wall and was discovered in the sinonasal tract, respectively. In the lung and breast, a highly unforeseen observation in this age group ie, two tumors nurtured exon 15 internal tandem duplications of BCOR, was made. Each of seven sarcomas comprised of dense proliferations of uniform round to spindle cells with fine chromatin within vascular stroma. Swirling fascicular growth was exhibited by BCOR-CCNB3 sarcomas. A multinodular growth of spindle cells and palisading of oval cells were exhibited by the tumor with the ZC3H7B-BCOR fusion and the tumors with the CIITA-BCOR fusion, respectively. Both tumors with BCOR internal tandem duplication exhibited nested to palisading growth of round cells within sclerotic non-myxoid stroma. BCOR and SATB2 were immunohistochemically and diffusely expressed in all seven sarcomas, with all three BCOR-CCNB3 sarcomas being immunopositive for CCNB3. BCOR alterations were validated via RNA sequencing, polymerase chain reaction, Sanger sequencing, and/or fluorescence in situ hybridization. Hence, this study extended the clinicopathologic and molecular spectrum of BCOR-associated sarcomas, and highlighted the significance awareness of this disease in the differential diagnosis of adult non-uterine sarcomas.