A 56-year-old Caucasian male presents to your office for a routine check-up. He complains of chronic cough, fatigue, and occasional headaches. He has longstanding hypertension, which is controlled with amlodipine and lisinopril. Three months ago, he was diagnosed with acute bronchitis and treated with a short course of antibiotics. He smokes one pack of cigarettes daily and consumes alcohol occasionally. He denies any recreational drug use. His family history is significant for prostate cancer in his father and renal cell carcinoma in his uncle. His blood pressure is 147/82 mmHg, pulse is 93/min, temperature is 36.7 C (98 F) , and respirations are 14/min. His oxygen saturation is 94% on room air. His BMI is 42 kg/m². Physical examination is unremarkable. His chest X-ray is normal. Item 1 of 2
Which of the following is the best next step in managing this patient?

Question

A 56-year-old Caucasian male presents to your office for a routine check-up. He complains of chronic cough, fatigue, and occasional headaches. He has longstanding hypertension, which is controlled with amlodipine and lisinopril. Three months ago, he was diagnosed with acute bronchitis and treated with a short course of antibiotics. He smokes one pack of cigarettes daily and consumes alcohol occasionally. He denies any recreational drug use. His family history is significant for prostate cancer in his father and renal cell carcinoma in his uncle. His blood pressure is 147/82 mmHg, pulse is 93/min, temperature is 36.7 C (98 F) , and respirations are 14/min. His oxygen saturation is 94% on room air. His BMI is 42 kg/m². Physical examination is unremarkable. His chest X-ray is normal.

Item 1 of 2
Which of the following is the best next step in managing this patient?

Quizplus · Accepted Answer

Explanation: The most notable abnormality in this patient's laboratory values is a markedly elevated hemoglobin/hematocrit level. This would qualify as polycythemia, which is considered when the hemoglobin level is greater than 16.5 g/dL in a woman or 18.5 g/dL in a man. Repeat testing is generally indicated to ensure that a spurious value has not been obtained. In the majority of cases, polycythemia is caused by chronic hypoxia secondary to cardiac or pulmonary disease. The presence of pulmonary disease is possible in this patient given his smoking history. The best initial test for determining the cause of polycythemia is a serum erythropoietin level. In polycythemia secondary to chronic hypoxia, a high serum erythropoietin level is expected as a compensatory mechanism to correct for the hypoxia. Erythropoietin may be inappropriately elevated in the presence of certain tumors that secrete the hormone, such as renal cell carcinoma. A low erythropoietin level would suggest polycythemia vera, a chronic myeloproliferative disorder. (Choice A)A bone marrow biopsy is unnecessarily invasive at this time, as the presence of a high erythropoietin level would essentially exclude polycythemia vera. (Choice B)Polycythemia can be caused by various neoplasms, particularly renal cell carcinoma, which could be detected with a CT of the abdomen. However, serum erythropoietin is a better first test because it helps to better characterize the cause of polycythemia and guide further diagnostic evaluation. (Choice D)Hemoglobin electrophoresis is most helpful when an abnormality is suspected in the hemoglobin molecule itself, such as in sickle cell anemia or the thalassemias. (Choice E)Serum iron and B12 levels are more helpful in the work-up of low hemoglobin. Educational Objective: Serum erythropoietin is a good initial diagnostic test for the evaluation of polycythemia and helps to guide the remainder of the work-up. A low erythropoietin level suggests polycythemia vera, whereas a high erythropoietin level suggests a secondary cause of polycythemia, such as chronic hypoxia or a hormone-producing neoplasm (commonly renal cell carcinoma).

A 56-Year-Old Caucasian Male Presents to Your Office for a Routine