Myeloproliferative neoplasmsDownloads

A 40-year-old man comes to the physician because of fatigue, increased sweating, and itching in his legs for the past 2 years. He has chronic bronchitis. He has smoked two packs of cigarettes daily for 24 years and drinks one to two beers every night. His only medication is a tiotropium bromide inhaler. His vital signs are within normal limits. He is 175 cm (5 ft 9 in) tall and weighs 116 kg (256 lb); BMI is 38 kg/m2. Physical examination shows facial flushing and bluish discoloration of the lips. Scattered expiratory wheezing and rhonchi are heard throughout both lung fields. Abdominal examination shows no abnormalities. Laboratory studies show: Erythrocyte count 6.9 million/mm3 Hemoglobin 20 g/dL Mean corpuscular volume 91 μm3 Leukocyte count 13,000/mm3 Platelet count 540,000/mm3 Serum Ferritin 8 ng/mL Iron 48 μg/dL Iron binding capacity 402 μg/dL (N: 251 - 406 μg/dL) Which of the following is the most appropriate next step in treatment?

A 47-year-old woman presents for a routine wellness checkup. She complains of general fatigue and lethargy for the past 6 months. She does not have a significant past medical history and is currently not taking any medications. The patient reports that she drinks “socially” approx. 6 nights a week. She says she also enjoys a “nightcap,” which is 1–2 glasses of wine before bed every night. She denies any history of drug use or smoking. The patient is afebrile, and her vital signs are within normal limits. A physical examination reveals pallor of the mucous membranes. Her laboratory findings are significant for a mean corpuscular volume of 72 fL, leukocyte count of 5,300/mL, hemoglobin of 11.0 g/dL, and platelet count of 420,000/mL. Which of the following is the most likely cause of this patient’s thrombocytosis?