Background: We are presenting a rare case of large non-familial left atrial myxoma in a fourteen year old girl which presented clinically similar to severe mitral stenosis which was the first clinical differential diagnosis which was considered initially. She had symptoms of progressively worsening orthopnea and exertional dyspnea since the last 2-3 months (NYHA class III symptom status). The final diagnosis which was made after echocardiography was surprising and the girl was diagnosed to have a large atrial myxoma which was causing obstruction of the mitral valve preventing normal inflow across the mitral valve. The patient had no family history of being diagnosed of a cardiac tumor nor there were any cutaneous manifestations in the form of lentigenes or any symptoms suggestive of and systemic or cerebral embolization of tumor fragments. The patient subsequently underwent surgical excision of the tumor which was eventually confirmed to be an atrial myxoma histopathologically. Presence of atrial myxoma in an adolescent patient is an extremely rare occurrence and has seldom been reported.
Key words: Atrial myxoma, non familial echocardiography.