An unusual cause of life-threatening right-sided heart failure: undifferentiated pleomorphic sarcoma in the right ventricular outflow tract

An 83-year-old woman presented with a rapidly progressing dyspnoea and generalized oedema that had developed over a few days. On admission, her blood pressure was 88/68 mmHg and her heart rate was 94 beats per minute. Echocardiography revealed an ellipsoidal mass measuring 20 × 28 mm, which occupied most of the right ventricular outflow tract (RVOT) (Panels A and B, Supplementary material online, Videos S1 and S2). Severe tricuspid regurgitation was detected with a peak pressure gradient of 78 mmHg (Panels C and D, Supplementary material online, Video S3). Parasternal short-axis view demonstrated a D-shaped left ventricular cavity caused by elevated right ventricular pressure (Panel E, Supplementary material online, Video S4). Computed tomography confirmed the mass in the RVOT with no evidence of pulmonary embolism (Panel F). Since her haemodynamic state was unstable due to the mass obstruction of RVOT, emergency surgery was performed. The mass was significantly fixed in the RVOT (Panel G). Cardiac tumour in the RVOT was surgically resected (Panel H), and RVOT reconstruction and pulmonary valve replacement were performed. Histological examination with haematoxylin–eosin staining revealed solid growth with pleomorphic, fusiform-shaped cells (Panel I). The tumour cells were immunoreactive for α-smooth muscle actin, partially positive for muscle-specific actin, desmin, and factor VIII, and negative for CD31, CD34, and S-100. Based on these findings, the tumour was finally diagnosed as undifferentiated pleomorphic sarcoma. Although cardiac sarcoma is an extremely rare finding in RVOT, such incidences can cause a life-threatening right-sided heart failure.