PTH and hyperparathyroidism: Initial laboratory evaluation revealed hypercalcemia (serum calcium 3.69 mmol/L, RR 2.0–2.6 mmol/L), hypophosphatemia (serum phosphorus 0.40 mmol/L, RR 0.67–1.04 mmol/L), and hyperparathyroidism (PTH 284.0 pg/mL, RR 15–68.3 pg/mL).