Inappropriate elevation of intact PTH in the presence of normocalcemia after successful surgery for primary hyperparathyroidism.

We describe here a patient with primary hyperparathyroidism who had high serum intact PTH levels for over 16 months after parathyroidectomy without signs of recurrence or persistence of the disease. The patient was a 48-year-old female who appeared well nourished (body mass index, 23.7). She was received subtotal gastrectomy as treatment for a duodenal ulcer at 44 years and 5 months old and had reached menopaused at 46 years of age. Hypercalcemia and a high serum intact PTH level were pointed out three months before admission to our institute. A bone densitometric study revealed that the bone mass of the lumbar spine was extremely reduced (0.636 g/cm2, Z score, -2.17) preoperatively and had not increased 29.5 months after parathyroidal adenomectomy (0.656 g/cm2, Z score, -1.97). Hyperparathyroidism, menopause and gastrectomy may have together contributed to the reduced bone mass. The postoperative persistently increased PTH levels in our patient suggest that the remaining parathyroid glands could have been altered during hypercalcemia, causing an increase in the set-point of PTH secretion by serum calcium or a decrease in the renal responsiveness to PTH during the disease.