CURRENT CONCEPTS: Thrombocytosis

Abstract

Thrombocytosis is usually discovered incidentally, but the differential diagnosis is important. In cases of reactive, or secondary, thrombocytosis, the underlying disease may require treatment. Clonal thrombocytosis, in contrast, is associated with both thrombotic and bleeding complications, and cytoreductive treatment may be necessary. This review also summarizes the current understanding of platelet production.