Thrombocytosis
An asymptomatic 55-year-old woman presented with thrombocytosis discovered 2 years earlier. Laboratory testing revealed the following: hemoglobin 13.1 g/dL, red blood cell count 5.04 × 10 9 /L, hematocrit 41.8%, mean corpuscular volume 83 fL, mean corpuscular hemoglobin concentration 31.3 g/dL, leukocytes 10.87 × 10 9 /L (neutrophils 43%, lymphocytes 45%, monocytes 5%, eosinophils 4%), and platelets 513 × 10 9 /L. Serum ferritin levels were low at 8 ng/mL. Physical examination was unremarkable. Serum