Case Report: Primary gallbladder undifferentiated small round cell sarcomas treated with gemcitabine, paclitaxel, bevacizumab and pembrolizumab achieved remarkable tumor regression
Undifferentiated small round cell sarcoma (USRCS) are a rare, aggressive group of tumors associated with rapid progression, metastasis, and poor prognosis. Preoperative diagnosis remains elusive, particularly for extraosseous variants, and effective tr…