Cardiac inflammatory pseudotumor: rapid appearance in an infant with congenital heart disease.

The rapid growth of an inflammatory pseudotumor in the right atrium of an infant with pulmonary valve stenosis and atrial septal defect is documented. Systemic manifestations, including fever, weight loss, leukocytosis, and hypergammaglobulinemia, suggested infection; the diagnosis was made after surgical resection. Sixteen months after surgery the infant is asymptomatic, and the hypergammaglobulinemia and leukocytosis have resolved. Trauma may have been the inciting factor for this inflammatory pseudotumor.