Primary hyperparathyroidism due to parathyroid carcinoma associated with pulmonary embolism

Parathyroid carcinoma (PC) is an uncommon disease affecting 0.5-5% of all patients with primary hyperparathyroidism. PC is characterized by the association of severe symptoms of hypercalcemia, high serum calcium and parathyroid hormone (PTH) concentrations and a palpable neck mass. Definitive diagnosis can only be made by histological study after surgery. We report the case of a 77-year-old man admitted to our hospital due to pulmonary embolism and hypercalcemia. The patient was initially diagnosed with primary hyperparathyroidism, but displayed the atypical clinical features described above. Due to clinical suspicion of PC, a surgical procedure was carried out. Diagnosis of parathyroid carcinoma was confirmed by histopathologic study.