Review Question - QID 215580

A 67-year-old male presents to the emergency department with hip pain of two days duration. He denies any recent trauma. He has a past medical history significant for metastatic lung cancer. Initial labs include an elevated the sedimentation rate and elevated alkaline phosphatase. Radiographs of the hip show no fracture with moderate osteoarthritis. A bone scan is negative for any bony metastatic lesions. You reassure the patient that his hip pain is unlikely to be metastatic disease and initiate conservative management of his hip osteoarthritis. You recommend further work up based on his laboratory abnormalities, however. What additional testing may help to explain his elevated alkaline phosphatase?