Although cardiac tumours are uncommon, cardiac myxomas account for more than fifty percent of all cases and are the most frequent primary cardiac tumour. They have a broad clinical spectrum, usually related to cardiac symptoms, peripheral embolic events or systemic manifestations. We present a case report of a 68-year-old man who presented with systemic symptoms and analytical features suggestive of an autoimmune disease. In the ensuing diagnostic procedures, a cardiac myxoma was found, and after surgical resection, both the systemic manifestations and the analytical abnormalities disappeared.