Age / Sex : 43 / F

chief complaint: a bony lesion of L2, found incidentally on medical check-up

What is your impression?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).

Courtesy : So Young Park, Kyung Hee University Hospital at Gangdong

Discussion

Answer:  Paget's disease

Findings:

Radiographs of the lumbar spine show sclerotic change with cortical thickening in the body of L2.

Sagittal reformatted and axial reformatted CT images of the lumbar spine show mixed sclerotic and lytic changes involving vertebral body and posterior osseous element of L2.

MR imaging of the lumbar spine shows heterogeneous signal intensity changes involving body and posterior osseous element of L2 on T2- and T1- weighted images. Enhanced MR images show heterogeneous enhancement in the body and posterior osseous element of L2.

Differential Diagnosis: metastasis, lymphoma, hemangioma

Discussion:

• A chronic skeletal disorder characterized by abnormal and excessive remodeling of bone


• Common in United Kingdom, Australia, New Zealand, Western Europe, and the United States


• Rare in Scandinavia, Asia, the Middle East, and Africa


• Variable clinical manifestations : asymptomatic, painful, deforming, and various and debilitating musculoskeletal complications


• Three major phases: the lytic phase (incipient active), the mixed phase (active), and the blastic phase (late inactive)


• The anatomic distribution
  
  
  
  • usually asymmetric
  
  
  • most commonly affected sites: the lumbar spine, pelvis, sacrum, femur, and cranium
  
  
  • less commonly affected sites: the shoulder girdle (proximal humerus & scapula)
  
  
  • infrequently affected sites: ribs, fibula, and small bones in the hands and feet
  
  
  
  




• Polyostotic disease (65-90%)


• Monostotic Paget disease appears to predominate in the axial skeleton.




• Radiography and CT
  
  
  
  • The lytic or incipient active phase: osteolysis
  
  
  • The mixed phase: osteolysis, coarsening and thickening of bone trabeculation, meshed disorganized trabecular (mosaic) pattern, cortical thickening, and osseous widening
  
  
  • The blastic or late inactive phase: osteosclerosis, coarsening of the trabeculae and cortical thickening with marked widening and enlargement of bones, transverse fatigue fractures ("banana fractures"), and multiple fractures and abnormal bone repair associated with the development of progressive bowing deformities in the long bones and pelvis; ivory vertebra, enlarged vertebral body with or without sclerosis, and enlargement of the posterior osseous elements in the spine
  
  
  
  
  
  


• MR
  
  
  
  • Three major patterns of signal intensity : signal intensity similar to that of fat (the most common), heterogeneous, relatively low T1 signal intensity and high T2 signal intensity (the second most common), and low signal intensity on both T1- and T2-weighted images (the least common pattern)
  
  
  
  
  
  


• Complications
  
  
  
  • Common complications: osseous deformities, fractures, osteoarthrosis, basilar impression, spinal stenosis, and neurologic abnormalities
  
  
  • Other less commonly encountered complications : bone tumor, soft tissue mass, osteomyelitis, extramedullary hematopoiesis, rheumatoid arthritis and its variants, and crystal deposition disease (1)
  
  
  
  

References:

1. Theodorou DJ, Theodorou SJ, Kakitsubata Y. Imaging of paget disease of bone and its musculoskeletal complications: Review. AJR Am J Roentgenol 2011;196:S64-75