Spindle Cell Sarcoma of the Left Atrium: An Extremely Rare and Challenging Tumour Often Masquerading as Left Atrial Myxoma

Spindle-cell sarcoma of the left atrium is an extremely rare diagnosis, with only 4 cases reported in the literature worldwide. We report on a 42-year-old man, who presented to the emergency department with dyspnea and decreased exercise tolerance. A computed tomography chest scan showed a large mass in the left atrium. Echocardiography demonstrated a significant gradient across the mitral valve. The patient had the mass excised in the operating room. He did well post-operatively. Eight months later, a repeat cardiac magnetic resonance imaging scan showed a recurrence. Right pneumonectomy was performed to ensure margins were clear. Although he has done well after surgery, his prognosis remains guarded.