A 61-year-old man comes to the emergency department due to 20 minutes of slurred speech while eating lunch at work. Two months ago, he had an episode of blurry vision in his right eye. The patient has a history of hyperlipidemia and hypertension and takes amlodipine and hydrochlorothiazide. He is an active smoker with a 35-pack-year history.
Blood pressure is 155/90 mm Hg and pulse is 78/min. Oxygen saturation is 94% on room air. BMI is 31 kg/m². The lungs are clear to auscultation. The spleen tip is palpable on inspiration. There is trace bilateral pedal edema.
Laboratory results are as follows:
Which of the following is the most likely additional finding in this patient?

Question

A 61-year-old man comes to the emergency department due to 20 minutes of slurred speech while eating lunch at work. Two months ago, he had an episode of blurry vision in his right eye. The patient has a history of hyperlipidemia and hypertension and takes amlodipine and hydrochlorothiazide. He is an active smoker with a 35-pack-year history.
Blood pressure is 155/90 mm Hg and pulse is 78/min. Oxygen saturation is 94% on room air. BMI is 31 kg/m². The lungs are clear to auscultation. The spleen tip is palpable on inspiration. There is trace bilateral pedal edema.
Laboratory results are as follows:

Which of the following is the most likely additional finding in this patient?

Quizplus · Accepted Answer

11ec193a_96d9_dac1_853d_c16faf83aa95_MD0002_00 This patient has polycythemia, which is defined as a hematocrit >48% in women and >49% in men. Although polycythemia can be seen with a number of different conditions, patients who have dramatic elevations in hematocrit (>18.5 mg/dL) and/or signs of hyperviscosity syndrome (eg, transient neurologic symptoms) are most likely to have polycythemia vera (PV). conditions PV is a clonal myeloproliferative disorder associated with the proliferation of red blood cells independent of erythropoietin (EPO) and other stimulating cytokines. As such, EPO levels are usually low. Most cases (>97%) are caused by mutations to JAK2 V617F. PV is often discovered incidentally when routine laboratory testing reveals elevated hemoglobin/hematocrit, but patients may also have: Aquagenic pruritus (36%)Erythromelalgia (29%) - burning pain in the feet or hands associated with erythema/cyanosis/pallorTransient visual disturbance (14%)Arterial or venous thrombosis (16%)Gastrointestinal symptoms Aquagenic pruritus (36%) Aquagenic pruritus (36%) Erythromelalgia (29%) - burning pain in the feet or hands associated with erythema/cyanosis/pallor Erythromelalgia (29%) - burning pain in the feet or hands associated with erythema/cyanosis/pallor Transient visual disturbance (14%) Transient visual disturbance (14%) Arterial or venous thrombosis (16%) Arterial or venous thrombosis (16%) Gastrointestinal symptoms Gastrointestinal symptoms Examination frequently reveals splenomegaly, facial plethora, and excoriations of the skin (from pruritus). Significant thrombocytosis is often present and may contribute to hyperviscosity and thrombus risk. Diagnosis is typically made by JAK2 mutation testing and bone marrow biopsy. Treatment for those with no active thrombus and at low risk for thrombus (eg, age <60, no prior thrombosis) includes serial phlebotomy, low-dose aspirin, and symptom control. Patients with active thrombus or greater risk for thrombus should also receive myelosuppressive therapy (eg, hydroxyurea). (Choice A) Renal cell carcinoma can present with hematuria and erythrocytosis (if the tumor produces EPO). However, thrombocytosis is rare and splenomegaly would be atypical. (Choice C) Philadelphia chromosome (BCR-ABL1 fusion gene) translocation t(9;22) is found in approximately 95% of chronic myelogenous leukemias (CML) and less frequently in acute lymphocytic and acute myelogenous leukemias. CML can cause thrombocytosis and splenomegaly but is not associated with erythrocytosis. In addition, most patients with CML have dramatic leukocytosis (often >100,000/mm³). ³ (Choice D) Patients with obstructive sleep apnea can have prolonged nocturnal desaturations, which can lead to secondary polycythemia. Hematocrit levels are typically mildly (not massively) elevated, and splenomegaly/thrombocytosis would be atypical. (Choice E) Vitamin B₁₂ deficiency usually presents with macrocytic anemia (not erythrocytosis). Thrombocytopenia and leukopenia can occur and frequently parallel the severity of anemia. ₁₂ Educational objective: Polycythemia vera is a myeloproliferative disorder due to clonal red blood cell proliferation that is erythropoietin (EPO)-independent. Most patients have low EPO levels and positive JAK2 mutation testing. Patients at low risk for thrombosis (eg, age <60, no prior thrombosis) are treated with serial phlebotomy, low-dose aspirin, and symptom control. Those at greater thrombus risk or with active thrombus also require myelosuppression. __________ References: How I treat polycythemia vera. (http://www.ncbi.nlm.nih.gov/pubmed/22611155) Cardiovascular events and intensity of treatment in polycythemia vera. (http://www.ncbi.nlm.nih.gov/pubmed/23216616)

A 61-Year-Old Man Comes to the Emergency Department Due to 20