A. Brief Descriptions：
2. Urate deposits progressively destroy the cartilage and soft tissue.
3. Urate crystals are water soluble so that the tissue must be fixed in absolute alcohol.
4. Needle-shaped doubly refractile crystals, deGalantha stain (+).
B. Gross Findings：
Opaque, whitish, chalk appearance.
C. Micro Findings：
Center: urate crystals disposed radially with an amorphous proteinaceous matrix.
Surrounded by an intense inflammatory reaction, composed of macrophages, lymphocyte, fibroblasts, and foreign body giant cells.
Robbins Pathologic Basis of Disease, 6th ed. P1253-1257.
【 Fig. 154a-1 (LP)】Urate crystal as amorphous pale-stained materials surrounded by intensely inflammatory reaction; note fibrotic bands in the periphery.
【 Fig. 154a-2 (LP)】Urate crystals (pale-stained) surrounded by foreign body type multinucleated giant cells and fibroblasts.