Parathyroid Crisis and Thromboembolism: Association or Coincidence?

Background/Objective: 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. Case Report: 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. Discussion: 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. Conclusion: 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.