Glomerular Diseases USMLE Step 1 Practice Question

A 36-year-old man comes to the physician for a 4-week history of swollen legs. He has difficulty putting on socks because of the swelling. Two years ago, he was diagnosed with sleep apnea. He takes no medications. He emigrated from Guatemala with his family when he was a child. He is 171 cm (5 ft 6 in) tall and weighs 115 kg (253 lb); BMI is 39 kg/m². His pulse is 91/min and blood pressure is 135/82 mm Hg. Examination shows periorbital and bilateral lower extremity edema. Laboratory studies show serum albumin 3.1 g/dL, total cholesterol 312 mg/dL, urine blood negative, urine protein +4, RBC 1-2/hpf, RBC casts negative, and numerous fatty casts. A renal biopsy is obtained. Which of the following is most likely to be seen under light microscopy of the patient's renal biopsy specimen?