In the examination of gout, what type of crystals are identified under polarized light microscopy?

In the examination of gout, the type of crystals that are identified under polarized light microscopy are needle-shaped crystals. These crystals are formed from monosodium urate, which results from elevated uric acid levels in the body. Under polarized light microscopy, these needle-shaped crystals exhibit strong negative birefringence, meaning they appear to have different colors when rotated, confirming their identity as urate crystals.

The presence of needle-shaped crystals is characteristic of gout and distinguishes it from other types of crystal-induced arthritis, such as pseudogout, which involves rhomboid-shaped crystals of calcium pyrophosphate dihydrate. Understanding the specific morphology and optical properties of these crystals is crucial for accurate diagnosis and management of gout.