Spontaneous pericardial hematoma in an infant.

The finding of a pericardial hematoma is rare in the pediatric population. Its occurrence in an otherwise healthy 3-month-old infant is unprecedented in the literature. The hematoma was initially identified by echocardiography. Computerized tomography and magnetic resonance imaging did not contribute to the identification of the mass. An exploratory thoracotomy was necessary to rule out a neoplastic process. The final diagnosis of hemorrhagic pericarditis was made.