Paradoxical scintigraphy bone scan findings with malignancy-associated extreme hypercalcemia

We report the first case of extreme hypercalcemia (Ca ²⁺ >6.0 mmol/L) as the initial presentation of de novo metastatic breast cancer. Following treatment and stabilization of the patient, imaging revealed a large breast mass and widespread osseous metastases. Whole body bone scintigraphy demonstrated significant extra osseous uptake of radiotracer in the lungs, liver, and kidneys-a rare phenomenon secondary to profound hypercalcemia. Biopsy revealed estrogen receptor (ER) positive breast carcinoma, for which the patient was treated.