<prompt> 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:Removal of all four glandsCalcitoninRemoval of all glands leaving 50 mg of tissue as remnantEnlarged glands to be removed  <response>: 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. 