Which type of synovial fluid crystal is translucent and appears as stacked panes of glass in hyperlipidemic states?

• A. Monosodium urate
• B. Cholesterol
• C. Calcium pyrophosphate
• D. Uric acid crystals

Answer: (B)

When looking at synovial fluid under the microscope, the shape and appearance of crystals point to different kinds of crystal-induced arthritis. The description of being translucent and arranged like stacked panes of glass is classic for cholesterol crystals. These crystals are flat, plate-like, and can align in the fluid to resemble thin, translucent sheets, especially in hyperlipidemic states where cholesterol can deposit in the joint.

By contrast, the common urate crystals are needle-shaped and show negative birefringence, while calcium pyrophosphate crystals are rhomboid and typically show positive birefringence. Those shapes and optical properties don’t match the stacked glass–pane appearance. Thus, the translucent, plate-like stacks in a hyperlipidemic context point to cholesterol crystals.