Figure 8.

Patient with a primary lymphoma in the semitendinosus muscle. (a) Sagittal T2-weighted fat-saturated MR image showing a T2 hyperintense tumour mass within the muscle (white arrow), long segmental involvement with orientation of the tumour along muscle fascicles (white arrowhead), traversing vessels within involved muscle (black arrowhead) and adjacent subcutaneous stranding (black arrow). (b) Axial T1 MR image showing a tumour of slightly increased signal intensity (white arrow) compared with normal muscles and a traversing vessel (black arrowhead). (c) Contrast-enhanced T1-weighted fat-saturated MR image (white arrow) with peripheral septal enhancement (white arrowhead). Traversing vessel noted again (black arrowhead). (d) Axial T2-weighted fat-saturated MR image showing a heterogeneous T2 hyperintense tumour (white arrow) and adjacent neurovascular bundle involvement (white arrowhead). (e) Prechemotherapy PET/CT with FDG shows the tumour to be FDG avid (white arrow). (f) Postchemotherapy PET/CT showing decrease in FDG avidity of the tumour (white arrow), compatible with treatment response.