RESUMEN
Cardiac tumors are rare neoplasms with an incidence of 0.027 cases per 100. Up to 90 % of these tumors are benign but, because of their location, they can be lethal, despite their histology. Most appear in infants aged less than 1 year. Teratomas, which are relatively frequent in the pediatric age group, are usually located in the ovaries, sacrococcygeal area, thorax, and retroperitoneal area. Intrapericardial location is less frequent. In this localization, the clinical manifestation depends on compression of adjacent structures and determines the therapeutic attitude in each case. Imaging studies should be performed and the definitive diagnosis is obtained after surgical resection, which is the treatment of choice. The differential diagnosis should include other tumors of the anterior mediastinum, thymus hypertrophy, pericardial effusion and primary cardiac disorders such as pericardial mesothelioma, Ebstein malformation, and intrapericardial bronchogenic cysts. We present two patients who were diagnosed in the first year of life in our hospital. Both children developed pericardial tumours. In one patient, the mass decreased and disappeared while in the other, who received a later diagnosis, surgical treatment was required.