Primary Pericardial Angiosarcoma Demonstrating Initial Response Followed by Progression on First‐Line Chemotherapy: A Case Report. - Thakur, Ujjwal Kumar; Subedi, Akash; Joshi, Rheecha; Dhanchha, Sunita; Yadav, Sumit; Pangyani, Binaya; Acharya, Ajaya; KC, Punam; Shrestha, Sunil; Prasai, Gerim; Adhikari, Abish; Jha, Anjani Kumar; et al. (Clinical Case Reports, 2026)