Review Question - QID 107772

Paget’s disease (osteitis deformans) is a metabolic bone disease that causes sclerotic and deformed bones that may demonstrate “cotton wool spots” and long bone bowing on x-ray.

Paget disease is the most common bone disorder after osteoporosis, with increased incidence in >50 years old. Paget’s disease is caused by accelerated bone resorption followed by deposition of dense, chaotic bone matrix mineralization resulting sclerosis and deformation. Up to 70% of patients are asymptomatic and others develop complications such as bone pain, deformity, nerve compression syndromes and fragility fractures. Elevated alkaline phosphatase is used as a biomarker of the disease. Patients may present with metabolic abnormalities such as hypercalcemia, hypercalciuria and hyperuricemia.

Josse et al. discuss the types of common radiologic findings in patients with Paget’s disease including: cotton wool spots, flame-shaped lesions in long bones, osteolytic lesions near thickened lesions, sclerotic bone, bowed limbs, transverse fractures. Among some of the most commonly affected limbs are the pelvis (72%), lumbar spine (58%), femur (55%), thoracic spine (45%) and skull (42%).

Delmas et al. discuss indications for therapy. Those with bone pain or those at risk of complications, (e.g: hearing loss or spinal cord compression) should receive anti-resorptive therapies. Second-generation oral bisphosphonate, such as alendronate, are a first line therapy. IV pamidronate, etidronate are acceptable alternatives. Calcitonin may be used to decrease bone pain rapidly.

Figure A demonstrates the “cotton wool spots”, ill-defined sclerotic and lucent areas throughout that is a finding of Paget disease . The cortex is thickened and irregular.

Incorrect answers:
Answer 1: Bony metastases are most commonly associated with primary tumors from breast cancer, prostate cancer and lung cancer. Common sites of bone metastasis include spine, pelvis, ribs, skull and proximal femur. This Patient has no symptoms suspicious for primary cancer.
Answer 2: Osteoarthritis is a common degenerative joint disease that results from breakdown of joint cartilage and underlying bone. Commonly affected joints include fingers, low back, knees and hips.
Answer 4: Osteitis fibrosa cystica is a skeletal disorder caused by hyperparathyroidism. Excess parathyroid hormone increases osteoclastic bone resorption. Patients have elevated serum calcium levels and form cyst-like brown tumors in and around bone.
Answer 5: Osteomalacia is the softening of bones caused by defective bone mineralization, most commonly caused by vitamin D deficiency. In adults, symmetric pain usually begins in the lumbar spine.