Molecular Genetic Analysis of a Rare Case of Undifferentiated Pleomorphic Sarcoma with Rhabdomyosarcomatous Differentiation: Insights from Whole-Exome Sequencing and Literature Review - Dong, Yajing; Xu, Jianhao; Pan, Lanfen; Li, Fang; Gao, Xiaojiao; Gu, Tingting; Gu, Jingfeng; Xu, Song; Deng, Zhiyong (AME Case Reports, 2026)