This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Commonest cause of raised serum calcium is - \nSelect and explain. \nA. Ecotopic secretion, B. Parathyroid hyperplasia, C. Parathyroid adenoma, D. Parathyroid carcinoma', 'role': 'user'}, {'content': "Answer: C \nExplanation: 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.", 'role': 'assistant'}]