AKT-4612

AKT-4612

A 70-year-old woman presents with severe sharp pain in the left groin following a minor fall and is unable to walk. Radiological examination reveals a left neck of femur fracture. Routine laboratory evaluation shows a serum calcium concentration of 1.8 mmol/l (normal range 2.20–2.60 mmol/l), a serum phosphorus concentration of 0.72 mmol/l (normal range 0.7–1.4 mmol/l) and increased serum alkaline phosphatase activity. The serum parathyroid hormone level was subsequently found to be elevated.
What is the most likely diagnosis?