Acute Pseudogout (Calcium Pyrophosphate Dihydrate Crystals)
Polarized light microscopy showing calcium pyrophosphate dihydrate crystals. Note the positive bifringence (blue) of rhomboid-shaped crystals versus the needle-shaped and negatively birefringent (yellow) crystals of gout. (Courtesy of Dr. A. Fam)
Crytstals – Pseudogout