58-year-old female is admitted for a work up for a complaint of neck and low bac

58-year-old female is admitted for a work up for a complaint of neck and low back pain. During admission, you discover that she underwent a renal transplant six years ago. The patient also had blood work collected. When you review the findings, you notice that her serum calcium is elevated at 13.9 (Normal values range from 8.5 to 10.2 mg/dl), her CBC shows a hematocrit of 33%, and hemoglobin of 11.1 g/dl (normal adult female hematocrit Range: 37-47%, normal adult female hemoglobin range: 12-16 g/dl).
What could be the underlying cause of her pain and her abnormal lab values?
What other assessments would be helpful?
What interventions might be considered?