Commonest cause of raised serum calcium is -

Ans. is 'c' i.e., Parathyroid adenoma o Primary hyperparathyroidism is the most common cause of hypercalcemia overall. o The frequency of the various parathyroid lesions underlying the hyperfunction is as follows : ? Parathyroid adenoma - 75% to 80% Primary hyperplasia - 10% to 15% Parathyroid carcinoma- < 5% o After hyperparathyroidism, malignancy is the 2nd most common cause of hypercalcemia by one of the following mechanisms. i) Osteolysis ii) Secretion of parathormone related peptide.