A 68-year-old man has experienced increasing malaise for 3 years. Physical examination shows no remarkable findings. Laboratory findings include a serum creatinine level of 4.9 mg/dL and a urea nitrogen level of 45 mg/dL. Abdominal CT scan shows small kidneys. Which of the following endocrine glandular lesions has developed secondary to the underlying disease in this patient?

Chronic kidney injury, often leading to small end-stage kidneys, with chronic renal failure can lead to secondary hyperparathyroidism resulting from decreased phosphate excretion by the kidneys. The resultant hyperphosphatemia depresses the serum calcium level and stimulates parathyroid gland activity. Because of reduced renal parenchymal function, there also is less active vitamin D, which leads to decreased dietary calcium absorption. Renal failure does not lead to any of the other endocrine lesions listed.