A 70-year-old woman presents with constitutional symptoms for several weeks and acute renal failure. Creatinine rose from a baseline of 80 µmol per liter to 180. Urinalysis was positive for blood and 3 g/L of protein. Microscopy is shown below. A renal biopsy was performed on the same day, light microscopy also appears below.
Which of the following is most compatible with this overall presentation?