Hemorrhaged left atrial myxoma presenting with acute heart failure: A case report.

Left atrial myxoma is the most common primary cardiac tumor, although intratumoral hemorrhage remains exceedingly rare. We recently treated a 55-year-old man with a 37-year smoking history who presented with progressive dyspnea and leg edema caused by acute heart failure. Echocardiography revealed a large, pedunculated left atrial mass (54 × 27 mm) protruding into the left ventricle during diastole, causing functional mitral stenosis, as well as moderate mitral and tricuspid regurgitation. Contrast-enhanced computed tomography revealed a 30 × 46 mm intracardiac mass without definite feeding vessels or signs of hemorrhage. The patient underwent semi-urgent surgery 1 week after diagnosis, with complete tumor excision and concomitant mitral and tricuspid annuloplasty. Histopathological examination revealed a 5.5 cm myxoid tumor containing multiple intratumoral hemorrhagic foci with hemosiderin deposition, consistent with hemorrhagic myxoma. The postoperative course was uneventful. Intratumoral bleeding within a myxoma may result from rupture of fragile neovessels, potentially leading to sudden enlargement and mitral inflow obstruction. Awareness of this rare condition is essential for timely clinical recognition and appropriate surgical decision-making in patients with deteriorating left atrial myxoma. Learning objective: To highlight that intratumoral hemorrhage in left atrial myxoma, although rare, can cause rapid tumor enlargement and acute mitral inflow obstruction. Recognition of early symptoms, such as unexplained cough and dyspnea, may facilitate timely diagnosis and prompt surgical intervention.