An intrapericardial teratoma is a rare tumor but it is the second most common cardiac tumor of childhood after rhabdomyosarcoma. A search of literature from 1966 until 1994 revealed 57 cases. Pericardial effusion is thought to be a hallmark of intrapericardial teratoma. We present a baby boy born at 38 weeks gestation that was diagnosed prenatally to have a mediastinal mass but its intrapericardial location was not diagnosed until surgery due to absence of pericardial effusion. After birth the baby was in respiratory distress and patient was operated the next day and subsequently discharged home in good condition. The pathology report showed a well encapsulated cystic structure measuring 4.5×4×2.2 cm. The cyst wall thickness varied from 0.5 to 0.8 cm. Microscopic examination showed a variety of well differentiated mature tissue derived from all three germ cell layers.

Analysis of the data from the literature plus our case showed that among 58 patients reported there were 50% males and 41% females (9% no data). Babies<3 mo and fetuses accounted for 72% of cases. Pericardial effusion was present in 70% and absent in 10%. (no data on 20%). All patients less than 3 mo old (including premature infants and fetuses) except our case had a pericardial effusion. Prenatal diagnosis of mediastinal mass was made in 11 cases. Intrapericardial localization of the tumor before operation or before autopsy was known in 40%. In all cases but three there was pericardial effusion that helped to diagnose intrapericardial localization. All three patients that were diagnosed preoperatively and did not have pericardial effusion were adults, 20, 32 and 54 years old. Only 4 tumors were malignant, 14 (24%) patients died because of intrapericardial teratoma and among them 5 were stillbirths and four patients died within 1 hour after birth. Operation was attempted in 75% (44 patients) with success rate of 95%. Although a pericardial effusion is usually present, its absence does not preclude the diagnosis of intrapericardial teratoma.