Aneurysmal Bone Cyst

  • Etiology: post-traumatic or reactive in nature
  • Radiograph: expansile lytic vascular lesion with septations and thin margin that may have soft tissue component, most common location is intradmedullary in metaphyseal long bones, also seen in spine most commonly lumbar where it is usually in posterior elements destroying pedicle and where it may expand into vertebral bodies and involve more than one level, can invade canal and cause cord compression
  • Bone scan: increased uptake
  • MRI: septae and fluid fluid levels due to methemoglobin
  • Clinical: primary seen in 10-30 year old, secondary seen in any age + associated with any bone lesion including primary bone malignancy

Cases of Aneurysmal Bone Cyst

Radiograph and MRI of aneursymal bone cyst
Lateral radiograph of the lumbar spine shows an expansile lesion in the S2 vertebral body. Axial and sagittal T2 MRI of the lumbar spine shows the S2 expansile lesion to be well defined and to have fluid-fluid levels within it.