Cardiologists evaluate cardiac masses after clinical symptoms lead to a positive imaging study, or because of an incidental mass found at imaging, usually echocardiography. Cardiac masses range from non-neoplastic lesions to high grade malignancies (box 1) and occur over a wide range of ages (table 1). Ninety per cent of primary cardiac tumours are either myxomas, which are cured by resection, or sarcomas, which have a dismal prognosis regardless of treatment (table 1).1^–5

Although the vast majority of heart tumour patients are readily referred to the surgeon (and eventually oncologist in the case of sarcoma), the rare patient with a heart tumour causes great interest among clinical cardiologists. Cardiac myxomas have a wide range of clinical presentations that may mimic a variety of non-neoplastic conditions. Most cardiac masses are not amenable to percutaneous biopsy; therefore definitive diagnosis often awaits surgical excision and allows for a time of suspense during which differential diagnoses are discussed. The 10% of heart tumours that are not myxoma or sarcoma comprise a quite varied group of lesions.

Cardiac masses that are discovered by imaging can be considered in three groups: paediatric tumours, which are mostly hamartomas and are associated in many cases with genetic syndromes; benign tumours, both non-neoplastic masses and benign neoplasms, which are generally cured by surgery; and malignancies, which are mostly primary cardiac sarcomas, but which include lymphoma and metastases (with known or occult primary) (box 1). In this article, tumours will be presented based on usual site in the heart, as differential diagnosis varies greatly by site (table 2). Primary tumours may arise in adults most frequently from the endocardium, followed by the cardiac muscle, and, most infrequently, the pericardium. Interestingly, the rate of metastatic lesions is the reverse; the pericardium is by far the most common …