Although definite diagnosis is most often made after surgical resection of the tumor, markedly elevated PTH and calcium levels (PTH > 1000 pg/mL and hypercalcemia >14 mg/dL (246)), severe end-organ involvement and a large parathyroid lesion with malignant-like ultrasonographic features with or without hoarseness and dysphagia should raise suspicion of parathyroid carcinoma (250, 251). This evidence concerns the gene PTH and Hypercalcemia.