Introduction Atrial myxoma is the most common benign primary cardiac tumour with 75% of myxoma originates from left atrium. It comprises of 50–85% of all primary cardiac tumour and incidence of 0.03% in general population. We present a case of giant left atrial myxoma with feeding vessel from left circumflex artery.

Case presentation A 69-year-old lady came to our centre to perform a routine echocardiogram due to mild symptom of shortness of breath. She has underlying hypertension, atrial fibrillation on warfarin therapy and previous history of mitral valve repair in 2005. Echocardiogram revealed LVEF 58%, enlarged left atrium with diameter of 67mm, mass seen at left atrium attached to interatrial septum with diameter 42 mm × 35 mm. Mechanical MVR opened well with no valves regurgitation noted. Cardiac MRI showed left atrial myxoma mass, diameter 50mm × 43mm and heterogenous component of haemorrhage, hemosiderin with calcification and fibrosis within. Severe left atrial enlargement and severe dilated left ventricle noted as well. Elective coronary angiogram subsequently arranged for coronary artery disease assessment. Coronary angiogram revealed large feeding vessel from left circumflex artery communicating with contrast staining over left atrial myxoma. Referral to cardiothoracic surgery done, decision was made for surgical removal of left atrial myxoma.

Discussion The clinical diagnosis of cardiac myxoma is often challenging because of its non-specific symptoms and signs. It can cause serious morbidity such as sudden cardiac death and systemic emboli if not treated promptly. Surgery remained the definitive treatment for this condition.

Conclusion Rare neovascularization originating from either right coronary artery or the left circumflex artery was reported in a left atrial myxoma. We want to highlight the importance of coronary angiogram to help decide priority of surgery.