Fibrous dysplasia (monostotic), left forearm

This code identifies a benign, localized bone disorder characterized by the replacement of normal bone with fibrous tissue and immature woven bone, specifically affecting the left forearm. It is a developmental anomaly of bone-forming mesenchymal tissue, leading to weakened bone structure.

Apply this code for patients diagnosed with fibrous dysplasia confirmed to be monostotic (single bone involvement) and located in the left forearm. Documentation should clearly specify the affected anatomical site and the monostotic nature of the condition.

• Ensure documentation specifies "monostotic" versus "polyostotic" to differentiate from other forms of fibrous dysplasia.
• Verify the laterality and specific bone involved (e.g., radius, ulna, or unspecified forearm bone).
• Do not confuse with other bone dysplasias or benign bone tumors; confirm the definitive diagnosis of fibrous dysplasia.