Atrial myxomas are the most common cardiac tumours in adults. They are usually found in the left atrium, but also occur in the right atrium. They are usually friable with a risk of embolization and may obstruct the mitral valve. Other common cardiac tumours in the adult include lipomas and papillary fibroelastomas. Once diagnosed, surgery is usually performed urgently due to the risk of embolization and obstruction to flow. However, if cerebral embolization has already occurred, surgery is usually deferred for a week.

Primary malignant cardiac tumours are very unusual in adults, but pose a technical challenge as they are characteristically infiltrative and often invade adjacent structures. More complex reconstruction of the atrium and adjacent structures may be necessary in these cases if surgery is performed. The most common primary malignant cardiac tumours are sarcomas.