Osteolysis, left forearm

This code signifies the pathological destruction or dissolution of bone tissue in the left forearm. It indicates a localized or generalized loss of bone substance, which can result from various underlying conditions.

Apply this code when documentation explicitly states osteolysis affecting the left forearm. This diagnosis is often supported by imaging studies (e.g., X-rays, CT scans) showing bone resorption or lesions, or by biopsy results.

• Ensure the documentation specifies "osteolysis" and not merely "bone loss" without further clarification of the pathological process.
• Always code any underlying cause of the osteolysis (e.g., tumor, infection, metabolic disorder) as a primary or secondary diagnosis.
• Verify laterality; this code is specific to the left forearm. Use M89.531 for the right forearm or M89.539 for unspecified.