Following surgery for a parathyroid hormone-secreting tumor, you would typically expect:
b. Decreased calcium levels in the blood
Parathyroid hormone (PTH) regulates calcium levels in the blood. A tumor in the parathyroid gland can lead to excessive secretion of PTH, which in turn increases calcium levels in the blood. Surgery to remove the tumor aims to correct this condition, leading to a decrease in blood calcium levels as PTH secretion returns to normal.