A 65-year-old woman presented incidentally with a high-normal serum calcium level (10.80 mg/dL [2.70 mmol/L]; reference range, 8.5-10.8 mg/dL [2.12-2.70 mmol/L]) after undergoing routine blood work 4 months earlier. The results of her physical examination were essentially unremarkable. A serum intact parathyroid hormone level was markedly elevated at 165 pg/mL (17.4 pmol/L) (reference range, 12-65 pg/mL [1.3-6.8 pmol/L]), and a 24-hour urinary calcium level was elevated at 425 mg (10.6 mmol/d) (reference range, 100-300 mg [2.5-7.5 mmol/d]). A sestamibi scan (Figure 1) demonstrated persistent accumulation of technetium Tc 99m tracer just right of the midline, posteroinferior to the thyroid lobes.
Seethala RR, Yim JH, Hunt JL. Pathology Quiz Case 2. Arch Otolaryngol Head Neck Surg. 2006;132(12):1391. doi:10.1001/archotol.132.12.1391