A 10 year old boy has a fracture of femur. biochemical evaluation revealed Hb 11.5 gm/dl and ESR 18 mm 1st hour. Serum calcium 12.8 mg/dL, serum phosphorus 2.3 mg/dL, alkaline phosphate 28 KA units and blood urea 32 mg/dl. Which of the following is the most probable diagnosis in his case –

You can solve the question just looking at calcium value. Amongst the given options only hyperparathyroidism causes hypercalcemia. The patient in question has an increased serum Ca', decreased serum phosphorus and increased values of alkaline phosphatase, all of which characterize hyperparathyroidism.