Refractory hypercalcemic crisis: A case of primary hyperparathyroidism with Gitelman syndrome

Area of Science:

• Endocrinology
• Nephrology
• Genetics

Background:

• Primary hyperparathyroidism (PHPT) causes hypercalcemia and hypophosphatemia due to excess parathyroid hormone.
• Gitelman syndrome (GS) is a rare salt-losing tubulopathy presenting with hypokalemia, hypomagnesemia, and hypocalciuria.
• Coexistence of PHPT and GS leads to complex electrolyte disturbances and refractory hypercalcemia.

Purpose of the Study:

• To report a case of refractory hypercalcemia due to coexisting PHPT and GS.
• To highlight the diagnostic challenges and management strategies for this rare combination.

Main Methods:

• Case report detailing clinical presentation, laboratory findings, and diagnostic workup.
• Inclusion of postoperative pathology and genetic testing for confirmation.
• Review of treatment interventions including zoledronic acid and denosumab.

Main Results:

• The patient presented with refractory hypercalcemia, hypophosphatemia, elevated PTH, hypokalemia, hypomagnesemia, and incongruous hypocalciuria.
• Conventional treatments failed, necessitating advanced therapies like zoledronic acid and denosumab.
• Diagnosis confirmed via pathology and genetic testing, revealing coexisting PHPT and GS.

Conclusions:

• Hypocalciuria in hypercalcemic patients, particularly with hypomagnesemia, suggests potential underlying Gitelman syndrome.
• Early diagnosis of coexisting PHPT and GS is crucial for effective management.
• Optimal treatment involves surgical correction of PHPT followed by management of GS-related electrolyte abnormalities.