Interstitial myositis, left shoulder

This code signifies inflammation of the connective tissue within the muscles of the left shoulder, specifically interstitial myositis. It indicates a non-infectious inflammatory process affecting the muscle fibers and surrounding interstitial tissue in this anatomical region.

Use this code for patients diagnosed with interstitial myositis affecting their left shoulder. Documentation should clearly specify the inflammatory nature of the myositis and its localization to the left shoulder, often supported by imaging findings or biopsy results.

• Ensure the documentation specifies "interstitial" myositis; other forms of myositis have different codes.
• Verify the laterality is explicitly stated as "left shoulder" to avoid miscoding.
• Consider co-reporting any underlying systemic conditions (e.g., autoimmune diseases) that may be causing the myositis.