1. Prepared by Mahalia Robinson, DO, MS and reviewed by Lori Sokoll, PhD.

An adult with a known history of multisystemic sarcoidosis presented to the emergency department with abdominal fullness, bilateral edema, weight gain and was found to have a significant acute kidney injury. They were placed on Prednisone 40 mg daily but did not tolerate it well. After further examination, they were found to have bilateral obstructive uropathy and received bilateral ureteral stents placed. They had a creatinine of 22.1 mg/dL (reference range: 0.5-1.5 mg/dL), BUN > 125 mg/dL (reference range: 8-25 mg/dL) and a Calcium of 13.8 mg/dL (reference range: 8.0-10.4 mg/dL).

Question: What is the most likely cause of his hypercalcemia?