Case of the Week

Sagittal (A) and axial (B and C) T2-weighted MRI of the spine shows intermediate/hyperintense lesions, some with small cysts of predominantly peripheral location, which involve the L5-S1 disc (white circles), sacrum, and left iliac bone (white arrowheads), with invasion of the spinal canal (thin red arrows), with contact and displacement of the left S1 nerve root (dotted white arrow), which is thickened. Involvement of the posterior paraspinal and left psoas muscles (green crosses), abdominal aorta, and both iliac arteries (thick yellow arrows) is also shown. Sagittal postcontrast T1WI (D) shows irregular peripheral enhancement (white arrow). Axial (E) STIR image of the thigh shows a hyperintense, multiseptated cystic lesion on the anterior aspect of the proximal left thigh, with small daughter vesicles on the periphery (white arrowhead). Axial T2WI of the abdomen (F) shows invasion of the aorta and right renal parenchyma (blue arrows) and left renal atrophy (yellow arrow).