The hyperthyroidism is associated to different clinical situations with a relative frequency on the daily practice. Anyway, there have been discovered and published some clinical cases of thyroid cancer with insufficient symptoms, associated with a typical clinical hyperthyroidism and that have been related with Graves Basedow Disease. We expose here two different kinds of non typical thyroid cancer as a contribution to medical literature. In these cases, thanks to a careful exploration, further tests and, above all, fine needle aspiration puncture, hidden cancer was discovered. Cancer was not expected because of clinical symptoms. The definitive treatment was marked by fine needle aspiration puncture.