Pericardial extramedullary hematopoiesis in a neonate with congenital heart disease. A case report.

A case of pericardial extramedullary hematopoiesis in a neonate with congenital heart disease was diagnosed by fine needle aspiration cytology. Undifferentiated blasts, promyelocytes, metamyelocytes and nucleated red blood cells were evident in the pericardial fluid specimen. The differential diagnosis of bone marrow contamination of pericardial fluid secondary to inadvertent sampling of neonatal hypodense bone tissue is also discussed. To our knowledge, this is the first reported case of neonatal pericardial extramedullary hematopoiesis associated with congenital heart disease.