Platelets > 450,000 / µl (Chronic) Isolated thrombocytosis Thrombocytosis associated with leukocytosis or elevated hemoglobin Isolated thrombocytosis Test for: CRP Iron, transferrin, ferritin Exclude prior splenectomy, asplenia CRP, Iron, transferrin, ferritin CRP increased Iron deficiency Normal CRP and no iron deficiency Evaluate for infection, inflammatory conditions, malignancy Evaluate for causes of iron deficiency Consider testing for: JAK2 mutation Serum erythropoietin level bcr-abl translocation OR Refer to Hematologist Consider absence of spleen as cause of thrombocytosis Back