A 78 y/o man with malaise presents with the following labora…

A 78 y/o man with malaise presents with the following laboratory data. Additionally his urine shows amino aciduria and phosphaturia. Oliguria is not present. A renal biopsy was performed. Images (LM, IF and EM) are shown. What is the best diagnosis?  Test Patient result Reference interval Serum albumin 4.5 g/dL 3.5-5.0 BUN, serum 18 mg/dL 9-25 Creatinine, serum 1.5 mg/dL 0.5-1.2 Fasting serum glucose 85 mg/dL 70-99 Hemoglobin A1c 5.0%

A 52 yo male with a longstanding history of diabetes and hyp…

A 52 yo male with a longstanding history of diabetes and hypertension now has advanced kidney disease. He presents in the Nephrology Clinic to make preparations to initiate dialysis. Below are his laboratory data.  Current Reference range Serum creatinine, mg/dL 4.5 0.5-1.2 Blood urea nitrogen, mg/dL 45 8-20 Serum Potassium, meq/L 5.0 3.3-5.1 Serum Calcium, mg/dL          9.9 8.4-10.2 Serum Phosphate, mg/dL   6.0 2.7-4.5 Parathyroid Hormone, pg/mL 350 12-88 Serum Albumin, g/dL 4.0 3.5-5.2  Which of the following is the most likely cause of this patient’s hyperphosphatemia in the setting of chronic kidney disease?