A 25-year-old man is brought to the physician because of fatigue, lethargy, and lower leg swelling for 2 weeks. He also noticed that his urine appeared darker than usual and for the last 2 days he has passed only small amounts of urine. His temperature is 37.5°C (98.6°F), pulse is 88/min, respirations are 15/min, and blood pressure is 154/98 mm. Blood urea nitrogen is 38 mg/dL and serum creatinine is 4.5 mg/dL. The patient undergoes a kidney biopsy and the following microscopic changes are seen after silver staining to highlight the glomerular tuft: The area marked with an arrow is likely to have abnormal deposition of which of the following substances?

Question

A 25-year-old man is brought to the physician because of fatigue, lethargy, and lower leg swelling for 2 weeks. He also noticed that his urine appeared darker than usual and for the last 2 days he has passed only small amounts of urine. His temperature is 37.5°C (98.6°F), pulse is 88/min, respirations are 15/min, and blood pressure is 154/98 mm. Blood urea nitrogen is 38 mg/dL and serum creatinine is 4.5 mg/dL.   The patient undergoes a kidney biopsy and the following microscopic changes are seen after silver staining to highlight the glomerular tuft:  The area marked with an arrow is likely to have abnormal deposition of which of the following substances?

Quizplus · Accepted Answer

Eductional Objective: Crescent formation on light microscopy is diagnostic for rapidly progressive glomerulonephritis.  Crescents consist of glomerular parietal cells, lymphocytes, and macrophages along with abundant fibrin deposition.  Crescents eventually become fibrotic, disrupting glomerular function and causing irreversible renal injury.

A 25-Year-Old Man Is Brought to the Physician Because of Fatigue