In primary hyperparathyroidism, what is the most common etiologic cause?

In primary hyperparathyroidism, what is the most common etiologic cause?

• A. Parathyroid hyperplasia
• B. Solitary parathyroid adenoma
• C. Parathyroid carcinoma
• D. Secondary hyperparathyroidism due to CKD

Answer: (B)

In primary hyperparathyroidism, the abnormality is autonomous overproduction of parathyroid hormone by the glands. The most common cause is a solitary parathyroid adenoma, a single gland that secretes PTH independent of the body's calcium level. This single-gland tumor accounts for the majority of cases—roughly around 80–85% (often cited as about 85–90%). The excess PTH drives hypercalcemia and its typical symptoms. Parathyroid hyperplasia, affecting multiple glands, is less common, and parathyroid carcinoma is rare. Secondary hyperparathyroidism due to CKD is a reactive condition driven by chronic hypocalcemia and phosphate retention, not a primary gland tumor.

In primary hyperparathyroidism, the abnormality is autonomous overproduction of parathyroid hormone by the glands. The most common cause is a solitary parathyroid adenoma, a single gland that secretes PTH independent of the body's calcium level. This single-gland tumor accounts for the majority of cases—roughly around 80–85% (often cited as about 85–90%). The excess PTH drives hypercalcemia and its typical symptoms. Parathyroid hyperplasia, affecting multiple glands, is less common, and parathyroid carcinoma is rare. Secondary hyperparathyroidism due to CKD is a reactive condition driven by chronic hypocalcemia and phosphate retention, not a primary gland tumor.