[Primary hyperparathyroidism. Postoperative normocalcemic hyperparathyrinemia after curative parathyroidectomy]

Area of Science:

• Endocrinology
• Surgical Oncology
• Metabolic Bone Disease

Background:

• Normocalcemic hyperparathyroidism, characterized by elevated parathyroid hormone (PTH) levels despite normal serum calcium, can manifest post-parathyroidectomy for primary hyperparathyroidism (pHPT).
• This condition may represent a normal recovery phase rather than persistent or recurrent disease.

Observation:

• A case report details a 62-year-old female with severe pHPT, showing significant PTH fluctuations (1072 to 13 pg/ml intraoperatively, rising to 287 pg/ml postoperatively).
• Long-term (7-year) follow-up revealed an inverse correlation between calcium and PTH levels, suggesting intact feedback mechanisms.
• Preoperative screening of 316 normocalcemic thyroid patients identified 9.8% with elevated PTH, but only one had parathyroid adenoma.

Findings:

• Late postoperative elevated PTH after successful pHPT surgery occurs in 21.5% of patients.
• Potential causes include reactive hyperparathyroidism, hungry bone syndrome, vitamin D deficiency, renal dysfunction, and lifestyle factors.
• An inverse calcium/PTH correlation suggests preserved feedback mechanisms.

Implications:

• Mild cases of postoperative hyperparathyrinemia may only require observation.
• Treatment strategies include calcium and vitamin D/calcitriol supplementation for hypocalcemia or deficiency.
• Ongoing hyperparathyrinemia necessitates an interdisciplinary diagnostic and therapeutic approach.