Primary cardiac tumours are a rare occurrence in clinical practice. Mural or pedunculated thrombi are other infrequent findings. These are usually associated with underlying heart disease, present in the left atrium or occupying aneurysms in the ventricular wall, usually the apex. The case of a 33-year-old woman with a pedunculated cardiac mass not having these latter characteristics is reported. She had experienced dyspnoea and lower extremity oedema for 3 years on referral. Echocardiography revealed a mass emerging from the interventricular septum, and a myxoma was suspected. Heart surgery was performed and the findings were a thrombus and large extent of septal and apical mural fibrosis. An endoaneurysmorraphy was performed with exclusion of fibrotic walls from the ventricular cavity.