Which statement about primary hyperparathyroidism is true?

Which statement about primary hyperparathyroidism is true?

• A. Most cases are due to a single adenoma
• B. Most cases involve carcinoma
• C. Calcium is usually decreased
• D. Vitamin D is usually deficient

Answer: (A)

Primary hyperparathyroidism mainly comes from autonomous overproduction of PTH, which drives hypercalcemia through increased bone resorption, enhanced kidney calcium reabsorption, and more intestinal calcium absorption via calcitriol. The most common cause in sporadic cases is a solitary parathyroid adenoma, making up the vast majority of situations. Multiglandular disease (hyperplasia) accounts for the rest, while parathyroid carcinoma is rare. So this pattern—one adenoma being the usual culprit—best reflects the typical etiologic picture. Calcium is elevated in primary hyperparathyroidism, not decreased, so that option wouldn’t fit. Vitamin D status can vary and is not a defining feature of the condition, so asserting it is usually deficient isn’t correct.

Primary hyperparathyroidism mainly comes from autonomous overproduction of PTH, which drives hypercalcemia through increased bone resorption, enhanced kidney calcium reabsorption, and more intestinal calcium absorption via calcitriol. The most common cause in sporadic cases is a solitary parathyroid adenoma, making up the vast majority of situations. Multiglandular disease (hyperplasia) accounts for the rest, while parathyroid carcinoma is rare. So this pattern—one adenoma being the usual culprit—best reflects the typical etiologic picture. Calcium is elevated in primary hyperparathyroidism, not decreased, so that option wouldn’t fit. Vitamin D status can vary and is not a defining feature of the condition, so asserting it is usually deficient isn’t correct.