Neuroimaging features of transitional cell carcinoma invading the lumbosacral plexus

Seventy-two-year-old with a history of bladder and prostate transitional cell carcinoma developed insidious pain, right leg weakness, and progressive foot drop. (A) Contrast-enhanced CT and (B) T2-weighted MRI show mass (arrows) in the right greater sciatic notch. Note diffuse T2 hyperintensity in the right gluteus medius muscle (arrowheads), consistent with muscle denervation. (C) Coronal pre- and (D) postcontrast T1-weighted MRIs show enlargement and enhancement of the right sciatic nerve secondary to infiltration by transitional cell carcinoma.