Maad Rayan Publishing Company Biomedicine Advances 3080-0382 2 4 2025 10 20 High-grade undifferentiated pleomorphic cardiac sarcoma extending from the interatrial septum to both atria and the anterior mitral valve annulus 207 209 10.34172/bma.34 EN Abidin Emre Tirnaksiz https://orcid.org/0009-0000-4413-6709 Arda Guler Ersin Kadirogullari Sinem Aydın Gonca Gul Gecmen Gamze Babur Guler Journal Article 10.34172/bma.34 2025 08 01 2025 09 26 Cardiac undifferentiated pleomorphic sarcomas are rare primary malignant tumors of the heart and constitute a significant portion of cardiac sarcomas. We present the diagnostic approach in a case of high-grade undifferentiated pleomorphic cardiac sarcoma with an unusual location in a 70-year-old woman.