Fig. 10
From: Nerve entrapment syndromes of the lower limb: a pictorial review
61-year-old male with chondrosarcoma in the left superior pubic ramus and anterior acetabulum. Axial T1 (a) and PDFS (b, c) sequences demonstrate the fluid-hyperintense intramedullary lesion with chondroid calcification (red circle). There is extraosseous extension into the left obturator foramen/canal, encroaching on the left obturator nerve (white arrow), resulting in nerve entrapment and secondary denervation oedema of the obturator externus, adductor brevis and magnus (yellow circle). CT reveals chondroid calcification of the tumour (blue circle) (d)