What condition is associated with rhomboid crystals that are positively birefringent?

The presence of rhomboid crystals that exhibit positive birefringence is indicative of pseudogout, which is also known as calcium pyrophosphate dihydrate (CPPD) crystal deposition disease. This condition occurs when calcium pyrophosphate crystals accumulate in the joints and surrounding tissues, leading to inflammation and pain, often resembling gout.

The characteristic morphology and optical properties of these crystals are essential for diagnosis. When viewed under polarized light microscopy, the rhomboid-shaped crystals of calcium pyrophosphate demonstrate positive birefringence, meaning that they appear bright against a dark background when rotated. This specific feature differentiates them from the needle-shaped crystals of monosodium urate found in gout, which display negative birefringence.

Understanding these differences helps in accurately diagnosing the type of crystal arthritis a patient may be experiencing. Pseudogout can lead to acute attacks similar to gout but is distinct in its underlying pathology and treatment strategies.