Delayed Calcium Normalization after Successful Parathyroidectomy in Primary Hyperparathyroidism

Abstract

Introduction: Parathyroidectomy is the curative treatment option in primary hyperparathyroidism (PHPT). The decrease of parathormone (PTH) by 50% or more from levels prior to surgery after excision predicts successful parathyroidectomy. Serum calcium is expected to return to normal within 24-72 hours after the surgery; however, nearly 10% have transient, persistent postoperative hypercalcemia. We present a case report of delayed calcium normalization after successful parathyroidectomy in a 38-year-old patient with PHPT.

Methods: Parathyroidectomy was performed, with evidence of a decrease in PTH levels of more than 50% in the first 24 hours postoperatively compared to presurgical PTH; however, despite curative parathyroidectomy, a delayed calcium normalization was evidenced, with hypercalcemia persistence up to 120 hours postoperatively.

Results: After the first month postoperatively, serum calcium remained normal. In conclusion, approximately 10% of patients with curative parathyroidectomy have transient, persistent postoperative hypercalcemia, which is more likely to occur in patients with higher preoperative serum calcium and PTH levels.

Conclusion: Persistent hypercalcemia after the first month postoperatively is related with persistent PHPT, highlighting the importance of calcium monitoring after parathyroidectomy to predict short-term, medium-term, and long-term outcomes and prognosis.

Figure 1

(a) Parathyroid adenoma. Hematoxylin-eosin stain (4x) showed the absence of adipose tissue and follicular (b) and trabecular (c) growth pattern, with a predominance of chief cells and some oxyphilic cells (d).

Figure 2

Evolution of serum PTH, calcium, phosphorus, and magnesium levels before and after parathyroidectomy. PreCx: presurgery. PostCx: postsurgery. ^∗Albumin-corrected calcium.