This is a benign tumor located in the left upper chamber of the heart (atrium) on the wall that separates the left chamber from the right (the atrial septum). See also atrial myxoma - right

A myxoma is a primary heart (cardiac) tumor. This means that the initial site of the growth was within the heart, which is uncommon with heart tumors. Most have spread from elsewhere in the body (metastasized).

Primary cardiac tumors are rare, but among them, myxomas are the most common. Over 80% of myxomas occur in the left atrium, usually beginning in the wall that divides the upper chambers of the heart (atrial septum) and growing into the atrium. However, right atrial myxoma may also occur.

Myxomas are more common in women.

Approximately 10% of all myxomas are familial, which means that they were genetically inherited. Familial myxomas tend to produce symptoms at a younger age than non-familial tumors and are often multiple, that is, are present in more than one site within the heart and can include the ventricles (lower heart chambers).