Idiopathic chronic gout, unspecified shoulder, with tophus

This code signifies a chronic inflammatory arthritis caused by uric acid crystal deposition, specifically in an unspecified shoulder joint, and characterized by the presence of tophi. Tophi are visible or palpable nodules of urate crystals that form in soft tissues, often around joints.

Apply this code when documentation confirms a diagnosis of chronic gout of unknown etiology affecting the shoulder, and explicitly states the presence of tophaceous deposits. This diagnosis is typically supported by clinical examination, imaging, and potentially aspiration of synovial fluid showing urate crystals.

• Ensure the documentation clearly specifies "idiopathic" and "chronic" gout, as well as the presence of "tophus" or "tophi."
• Do not use this code if the laterality of the shoulder is specified (e.g., right or left); instead, select a more specific M1A.01- subcategory.
• Distinguish from acute gout (M10.-) or gout due to other causes (M1A.1-M1A.9).