Parathyroid Crisis and Thromboembolism: Association or Coincidence?

The association between hypercalcemia and the risk of thromboembolic events is not clearly understood. Here, we present a unique case of a patient diagnosed with bilateral pulmonary thromboembolism in the setting of a parathyroid crisis due to primary hyperparathyroidism (PHPT). Our case may suggest a potential correlation between thromboembolism and PHPT with severe hypercalcemia. Nowadays just a few case reports provide support for this association, particularly in the settings of significant calcium and parathyroid hormone (PTH) derangement.

A 70-year-old woman presented to the hospital with a few weeks' onset of fatigue, difficulty walking, and shortness breath. Laboratory investigations revealed significantly elevated serum calcium (19.2 mg/dL) and PTH (1156 pg/mL) levels. Her past medical history was significant for PHPT with mild hypercalcemia since 2014. Computerized tomography and thyroid ultrasound of the neck showed a high suspicion of a left parathyroid adenoma. A computerized tomography angiogram of the chest revealed a bilateral lower lobe pulmonary embolism. The patient underwent medical management for hypercalcemia and pulmonary embolism, followed by parathyroidectomy. Pathology reports confirmed the diagnosis of parathyroid adenoma.

The clinical significance of hyperparathyroidism, leading to subsequent hypercalcemia and its association with the development of a procoagulable state, has been elucidated in a very limited number of case reports.

This case suggests that parathyroid crisis with hypercalcemia could potentially provoke thromboembolic events. However, this phenomenon could be explained by an extremely high level of PTH and calcium.