A 69 year old male presents with an episode of slurring of speech which lasted for 12 hours and then resolved.He is heavy smoker having smoked 60 cigarettes per day for 40 years. He had a single episode of haemoptysis 4 weeks previously and has underlying lung cancer with brain metastases and is referred for an urgent CT chest. An ECG was performed which showed new AF. All blood tests including cardiac biomarkers were normal. Chest CT is shown. Which of the following is most probable diagnosis?

The axial image from a contrast enhanced CT scan, in aerial phase, shows a filling defect in the left atrial appendage layered along the anterior wall. Given the clinical history and the CT appearance, the most likely diagnosis is of thrombus in the LA as a consequence of AF. Myxomas generally arise from interatrial septum projecting into the left atrium Vegetation, abscess and new dehiscence of a prosthetic valve are the three major echocardiographic criteria for the diagnosis of infective endocarditis.