Presentation
Dorso-lumbar mass.
Patient Data
There is a very large lobulated extradural right paravertebral mass lesion involving the pedicle of T12 extending into the vertebral body and inside the spinal canal pushing the whole thecal sac and spinal cord to the left side. This mass lesion has a fluid-fluid level and measures about seven by five centimeters.
The appearances are consistent with an aneurysmal bone cyst.
Case Discussion
This 14-year-old girl presented with a dorso-lumbar mass. Upon MRI evaluation of the spine, a multilocular extradural right paravertebral mass with multiple fluid-fluid levels was demonstrated. Appearances were suggestive of an aneurysmal bone cyst. The lesion was biopsied and results are shown below.
Histopathology report:
Gross exam: Specimen is received and fixed in formalin, labeled with the patient's name and consists of cystic hemorrhagic mass measuring 6.5 x 6 x 2 cm. Representative sections are submitted in 4 cassettes.
Microscopic exam: Sections reveal cystic spaces containing blood with no apparent endothelial lining surrounded by solid cellular areas composed of plump fibroblasts, osteoclasts-like multinucleated giant cells, and focal osteoid trabeculae. Focal aggregates of hemosiderin-laden macrophages are seen. No malignancy noted.
Diagnosis: Consistent with aneurysmal bone cyst.