MRI diagnosis of brown tumor based on magnetic susceptibility.

A 56-year-old male with chronic renal failure was incidentally found to have lytic bone lesions in the pubic symphysis, left femoral head, left acetabulum, left iliac bone, and L1 vertebra on computed tomography (CT). Subsequent magnetic resonance imaging (MRI) of the abdomen was performed (for evaluation of a renal lesion) which demonstrated marked loss of signal intensity in the L1 bone lesion on increasing TE gradient echo images, consistent with magnetic susceptibility effect due to hemosiderin. Brown tumor was confirmed at biopsy.