Fig 6. Pathology (A) central fragment of eroded bone surrounded by gouty tophi which are rimmed by multinucleated giant cells and fibrous tissue (hematoxylin-eosin x10). B, Needle-shaped crystals exhibiting strong negative birefringence (bright yellow when aligned parallel with the compensating filter) characteristic of monosodium urate crystals (gout; polarized light, x50).