Intrapericardial teratoma in the newborn.

Two cases of intrapericardial teratomas occurring in the newborn are reported. The first was a cystic, well differentiated tumour which was totally excised. The child was alive and well with no evidence of the disease 10 months later. The second was a predominantly solid teratoma which consisted of both mature and immature tissues. It was removed but recurred 2 months later with pleural and pericardial invasion. The patient underwent reoperation but death occurred 9 days after surgical treatment. The recurrence was histologically similar to the primary tumour. The second case is probably the first malignant intrapericardial teratoma described in a neonate. Its morphology and clinical behaviour suggest that, as in ovarian and sacrococcygeal teratomas, the presence of immature neuroepithelium carries a poor prognosis. In such cases radio- or chemotherapy should be performed.