Presentation
Sacral pain.
Patient Data













An expansile bone lesion is seen involving the posterior elements of S2 and S3 vertebrae, more on left side. It is encroaching upon thecal sac and compressing the left sided lateral recesses and exit foramina.



















An expansile bone lesion involving the posterior elements of S2 and S3 vertebrae, more on left side. It is encroaching upon thecal sac and compressing the left sided lateral recesses and exit foramina. It shows multiple fluid-fluid levels on T2 with hypointense signal of the dependent layer.
Case Discussion
The presence of multiple fluid-fluid levels is suggestive of an aneurysmal bone cyst. It often presents within the first two decades of life. The differential diagnosis includes telangiectatic osteosarcoma, chondroblastoma, giant cell tumour, metastatic disease, and multiple myeloma.