Which of the following is NOT a deposition site for uric acid crystals in gout?

• A. Joints
• B. Soft tissues
• C. Brain
• D. Kidneys

Answer: (C)

Gout involves deposition of monosodium urate crystals in places where the crystals are most likely to form and persist: the joints and surrounding soft tissues, and the kidneys. Joints and periarticular soft tissues are common targets because crystals accumulate in cooler, peripheral areas and provoke inflammatory arthritis and tophi. The kidneys are involved as uric acid is filtered and excreted, so crystals can form there, leading to uric acid stones or nephropathy. The brain is not a typical site for urate crystal deposition; the brain is protected by the blood-brain barrier and remains a warmer, less favorable environment for crystal formation. So the brain is not a deposition site in gout.