A 61 year-old male comes to your office reporting headaches, dizziness, tinnitus, vertigo, blurred vision, and easy bruising. He feels miserable after a warm shower because his whole body itches intensely. In a dinner party last weekend, his nose bled profusely. His fingers and toes become red, painful with burning sensations and warmth. He takes low-dose aspirin for relief from the pain and redness. His past medical history is significant for deep venous thrombosis in the right lower extremity 3 months ago. He has a history of smoking one or two cigarettes a day for over 10 years. His temperature is 99 °F (37.2 °C), heart rate is 108 beats/min, blood pressure is 164/105 mm Hg, respirations are 19 breaths/min, and oxygen saturation is 99% on room air. Physical examination is remarkable for engorged retinal veins, tenderness in the epigastric region (probably due to peptic ulcer disease) and splenomegaly. Laboratory results are given below: Erythrocyte count (RBC) 7.9 million/mm³ Male: 4.3 – 5.9 million/mm³ Female: 3.5 – 5.5 million/mm³ Hematocrit 61% Male:41% – 53% Female: 36% – 46% Hemoglobin, blood 21 g/dL Male:13.5-17.5 g/dL Female 12.0 – 16.0 g/dL Hemoglobin A₁c 5.6% ≤6% Leukocyte count (WBC) 16,754 /mm³ 4500-11,000/mm³ Neutrophils, segmented 84% 54% – 62% Neutrophils, bands 12% 3% – 5% Eosinophils 7% 1% – 3% Basophils 3% 0% – 0.75% Platelet count 1,200,000 /mm³ 150,000 – 400,000/mm³ Iron 63 µg/dL Male: 65 – 175 µg/dL Female: 50 – 170 µg/dL Total iron-binding capacity 410 µg/dL 250 – 400 µg/dL Transferrin 385 mg/dL 200 – 360 mg/dL Erythropoietin (EPO) 6.8 mg/dL 2.6 – 18.5 mg/dL Vitamin B12 1750 pg/mL 160 – 950 pg/mL Carboxyhemoglobin 2.7% <2.5% Uric acid 8.9 mg/dL 3.5 - 7.2 mg/dL Bone marrow film shows hypercellular marrow with erythroid, granulocytic, and megakaryocytic hyperplasia without overt dysmorphia of cells and normal maturation sequence, normal RBC, WBC, platelet morphology. Prussian blue stain reveals absence of iron. What is the most likely diagnosis in this patient?
