When you see a patient with cognitive dysfunction, hypercalcemia due to hyperparathyroidism is an important differential diagnosis. It is important to consider including chest computed tomography and 131I-MIBI SPECT examinations in patients with possible hyperparathyroidism and normal thyroid ultrasound.
Keywords: 131I‐MIBI; ectopic parathyroid adenoma; hypercalcemia; hyperparathyroidism.