Neonatal thrombocytosis following G-CSF treatment

Thrombocytosis is defined as an elevetion of the platelet count to more than 500,000/mm3 (1,2). Primary thrombocytosis rarely occurs in the pediatric age group and is usually caused by a clonal bone marrow disorder (3). The more common phenomenon is secondary thrombocytosis which is a reactive process. Table 1 lists the main causes of secondary thrombocytosis (1,3-123, 12). Complications of severe thrombocytosis include bleeding and thromboses. Unless additional risk factors are present, secondary thrombocytosis is not associated with a significant risk of thromboembolic events, regardless of the degree of elevation of the platelet count (3). The aim of this case report is to add a new possible cause of neonatal thrombocytosis.