Paget Disease of the Rib

General Considerations

• Multifocal chronic skeletal disease due to chronic paramyxoviral infection
• Prevalence
• 3% of individuals >40 years
• 10% of persons >80 years
• Unusual <40 years
• M:F = 2:1
• Pelvis most commonly involved
• Histology
• Increased resorption and increased bone formation
• Newly formed bone is abnormally soft with disorganized trabecular pattern

Clinical Findings

• Asymptomatic (1/5)
• When symptomatic, symptoms may include
• Fatigue
• Enlarged hat size
• Peripheral nerve compression
• Neurologic disorders from compression of brainstem (basilar invagination)
• Hearing loss, blindness
• Facial palsy (narrowing of neural foramina) - rare
• Pain from(a)primary disease process is rare so think of
• Pathologic fracture
• Malignant transformation
• Secondary degenerative joint disease aggravated by skeletal deformity
• High-output congestive heart failure from markedly increased perfusion (rare)
• Increased alkaline phosphatase (increased bone formation)
• Hydroxyproline increased (increased bone resorption)
• Normal serum calcium + phosphorus

Imaging Findings

• Characteristic changes of Paget’s disease of bone include
• Thickening of the cortex
• Coarsening of the trabecular pattern, and
• Increased size of the bone

Differential Diagnosis

• Metastatic disease
• Fibrous dysplasia

Paget Disease, right 6th rib. The rib is enlarged. The cortex is thickened (white arrows) but the medullary space remains intact (red arrow) with no evidence of infiltration.