A 73-year-old man complains of right leg pain of 2 years’ duration...

A 73-year-old man complains of right leg pain of 2 years’ duration. There is no history of falls or injury. In the past he has been admitted to hospital for cardiac failure and takes inhaled bronchodilators and steroids for chronic obstructive pulmonary disease.
Examination shows a healthy elderly man with mild tenderness of his right leg only.
Routine blood tests show normal serum calcium and phosphate levels with a markedly raised alkaline phosphatase level.

What is the most likely diagnosis?
A. Osteoartritis of the hip
B. Bony metastasis from an occult malignancy
C. Multiple myeloma
D. Paget’s disease
E. Osteomalacia

Answer:
D. Paget’s disease

Discussion: Paget’s disease of the bone is a disorder of bone remodelling. There is uncontrolled bone
turnover with excessive resorption, followed by disordered osteoblastic activity, which leads to
abundant new bone formation. It is common in Europe, where it affects 10% of adults by the age
of 90 years.
The femur, pelvis, tibia, skull and lumbosacral spine are commonly involved. It presents with bony
pain, deafness due to nerve compression, high-output cardiac failure and deformities. The serum
alkaline phosphatase level is markedly raised, with normal calcium and phosphate levels.
Treatment is indicated for the bone pain and can range from simple analgesics to diphosphonates
and calcitonin.