<p>Cardiac myxomas are the most common primary cardiac tumors and typically arise from the left atrium. Although histologically benign, large and highly mobile myxomas may cause severe hemodynamic compromise and mimic valvular heart disease or heart failure syndromes. We present a pictorial essay illustrating the echocardiographic appearance and functional consequences of a giant left atrial myxoma in an elderly patient presenting with progressive dyspnea and signs of congestion. Transthoracic echocardiography revealed a large pedunculated mass attached to the interatrial septum, occupying the left atrium and dynamically prolapsing through the mitral valve during diastole, resulting in functional obstruction and severe mitral regurgitation. Surgical excision confirmed the diagnosis and led to complete clinical recovery. This pictorial essay highlights key echocardiographic features, hemodynamic effects, and teaching points relevant for diagnosis, differential assessment, and follow-up of atrial myxomas.</p>