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: Surgery
[{'content': 'A female with frequent history of renal stones presented with severe bone pain. Laboratory findings are indicative of primary hyperparathyroidism which is secondary to parathyroid hyperplasia. Treatment is: \nSelect and explain. \nA. Removal of all four glands, B. Calcitonin, C. Removal of all glands leaving 50 mg of tissue as remnant, D. Enlarged glands to be removed', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Primary parathyroid hyperplasia involves all of the parathyroid glands. Microscopically, there are two types: chief cell hyperplasia and water-clear cell (wasserhelle) hyperplasia. Hyperplastic glands vary considerably in size but are usually larger than normal (65 mg). When all parathyroid glands are hyperplastic, the gland should be subtotally resected, leaving a 50 mg remnant, and confirmed histologically before removal of the remaining glands. The upper thymus and perithymic tract should be removed in patients with hyperplasia, because a fifth parathyroid gland is present in 15% of cases. Ref: Dohey G.M. (2010). Chapter 16. Thyroid & Parathyroid. In G.M. Dohey (Ed), CURRENT Diagnosis & Treatment: Surgery, 13e.', 'role': 'assistant'}]