What is the expected finding in a joint aspirate of a patient with gout?

In a patient with gout, the expected finding in a joint aspirate is needle-shaped crystals that demonstrate negative birefringence under polarized light microscopy. Gout results from the deposition of monosodium urate crystals due to elevated uric acid levels in the blood, which can lead to the characteristic inflammatory arthritis associated with the condition.

When joint fluid is examined, the needle-shaped crystals can be identified, and under polarized light, they exhibit negative birefringence, meaning they appear yellow when aligned parallel to the compensator and blue when perpendicular. This polarized light microscopy finding is key to distinguishing gout from other types of arthritis, such as pseudogout, which is caused by calcium pyrophosphate dihydrate crystals that have a different morphology and exhibit positive birefringence.

The presence of these specific crystals helps confirm the diagnosis of gout and is a critical component in the clinical management of the condition, guiding appropriate treatment strategies.