A 42-year-old man is brought to the emergency department 1 hour after the onset of severe headache, nausea, vomiting, and confusion. The patient has primary (essential) hypertension and chronic kidney disease; he has been prescribed 2 antihypertensive agents but has been noncompliant with therapy. Temperature is 36.8 C (98.2 F), blood pressure is 240/150 mm Hg, heart rate is 90/min, and respirations are 20/min. Ophthalmologic examination shows bilateral papilledema. The lungs are clear to auscultation. Cardiac examination reveals an S4 and no murmurs. Laboratory results are as follows: If renal biopsy is performed in this patient, which of the following pathologic findings is most likely to be found?

Question

A 42-year-old man is brought to the emergency department 1 hour after the onset of severe headache, nausea, vomiting, and confusion.  The patient has primary (essential) hypertension and chronic kidney disease; he has been prescribed 2 antihypertensive agents but has been noncompliant with therapy.  Temperature is 36.8 C (98.2 F), blood pressure is 240/150 mm Hg, heart rate is 90/min, and respirations are 20/min.  Ophthalmologic examination shows bilateral papilledema.  The lungs are clear to auscultation.  Cardiac examination reveals an S4 and no murmurs.  Laboratory results are as follows:  If renal biopsy is performed in this patient, which of the following pathologic findings is most likely to be found?

Quizplus · Accepted Answer

Hypertensive emergency is a condition defined as severely elevated blood pressure (typically >180/120 mm Hg) with evidence of ongoing end-organ damage (eg, renal injury). Hypertensive emergencies typically occur in patients with preexisting essential hypertension and may be induced by medication noncompliance, which can result in a rapid increase in systemic blood pressure. Severe hypertension can cause damage to the vascular endothelium, leading to increased vascular permeability to coagulation factors (eg, fibrinogen), platelet activation, and endothelial cell death. In the kidney, this manifests as malignant nephrosclerosis, which is characterized by 2 distinct histopathologic patterns: Fibrinoid necrosis: Cell death and excessive fibrin deposition within the arteriolar walls is visible as circumferential, amorphous, pink material with smudged, necrotic endothelial cells that lack cytologic detail. Hyperplastic arteriolosclerosis: Over time, activated platelets and injured cells release growth factors, which induce concentric hyperplasia and layering of smooth muscle cells and collagen, resulting in intimal thickening and an "onion-skin" appearance. These changes result in narrowing and/or obliteration of the arteriolar lumen; the resultant erythrocyte fragmentation and platelet consumption can cause a microangiopathic hemolytic anemia that is histologically indistinguishable from hemolytic uremic syndrome. Laboratory abnormalities reflect renal injury (eg, elevated creatinine and blood urea nitrogen) and hemolytic anemia (eg, schistocytes [fragmented red blood cells] on peripheral smear, elevated lactate dehydrogenase and indirect bilirubin). Other end-organ manifestations of hypertensive emergency include papilledema, retinal hemorrhages, pulmonary edema, acute coronary syndrome, encephalopathy, and stroke. (Choices B, D, and E) Hypertensive nephrosclerosis is characterized by interstitial fibrosis, tubular atrophy, and varying degrees of glomerulosclerosis (focal or global). Hyaline arteriolosclerosis is characterized by homogeneous deposition of hyaline material in the intima and media of small arteries and arterioles. These changes may be seen in chronic hypertension; however, the severely elevated blood pressure and evidence of end-organ dysfunction in this patient suggest hypertensive emergency and malignant nephrosclerosis. (Choice C) Granulomatous inflammation of the media characterizes temporal (giant cell) arteritis, the most common form of systemic vasculitis in adults. Educational objective: Hypertensive emergency is severely elevated blood pressure (typically >180/120 mm Hg) with evidence of end-organ damage. In the kidneys, this can manifest as malignant nephrosclerosis, characterized by fibrinoid necrosis and hyperplastic arteriolosclerosis ("onion-skin" appearance). A microangiopathic hemolytic anemia can occur due to erythrocyte fragmentation and platelet consumption at the narrowed arteriolar lumen.

A 42-Year-Old Man Is Brought to the Emergency Department 1