A rare disease of primary cardiac intimal sarcoma at the left atrium presented with mimicking mitral stenosis in a patient with polycystic kidney disease.

A 55-year-old woman presented with a history of constitutional symptoms with exertional dyspnea, orthopnea, and cough for one month. She developed progressive heart failure symptoms. Initial computed tomography revealed a large left atrial mass with compression of pulmonary veins and mitral valve. Surgical resection was performed, and histologic examination revealed an intimal sarcoma. The most effective treatment has been found to be a surgical resection, with chemotherapy and radiotherapy. The objective of this report is to describe a common presentation of a rare disease, and to discuss the significance of appropriate diagnosis, pathological findings, and timely interventional management. <Learning objective: Cardiac intimal sarcomas are rare primary malignant tumors. It requires a clinical suspicion for timely diagnosis and intervention, which could result in a good prognosis.>.