Figure 2
Case 1: (A) T1-weighted and B) STIR sagittal MRI images showing a mildly heterogeneous, well-defined, expansile intramedullary lesion that is confined within the bone with the exception of a nubbin of tumour that has breached the posterior cortex (arrowed). (C) Biopsy histology shows a malignant round cell tumour. (D) Tumour cells strongly express CD99.