Which stone type is commonly radiolucent and associated with gout?

• A. Uric acid stones
• B. Calcium oxalate stones
• C. Struvite stones
• D. Cystine stones

Answer: (A)

Uric acid stones are radiolucent on plain X-ray because uric acid does not block X-rays well. Gout involves high levels of uric acid in the body, which increases the likelihood of uric acid crystallization in the urine and, under acidic urine conditions, formation of uric acid stones. This combination—radiolucent appearance and association with hyperuricemia from gout—makes uric acid stones the best answer. Calcium oxalate stones are typically visible on X-ray (radiopaque), struvite stones are usually radiopaque and linked to infection, and cystine stones are not specifically tied to gout and are often radiolucent but less characteristic for this association.