The finding of intracardiac masses is very uncommon. In this patient the early clinical picture was characterized by neurologic signs and symptoms as mild forgetfulness, blurred vision, a sensation of imbalance, anorexia, weight loss. Brain magnetic resonance imaging showed multiple metastatic lesions, computed tomography of the chest, abdomen and pelvis showed intraatrial masses and whole body nuclear scanning evidenced bone lesion. It was not possible to find the primary tumor by other instrumental or laboratory exams. Transesophageal echocardiography showed a mass originating from interatrial septum, with atrial invasion and risk of embolization from the left atrium. The patient was transferred to the operating room for cardiac surgery, the mass at risk for embolization was resected and the specimen consisted of fibrous and fibrino-necrotic tissue infiltrated by poorly differentiated adenocarcinoma. The patient received brain and bone radiotherapy and chemotherapy with cisplatin and vinorelbin.