Fibrous dysplasia (monostotic), left upper arm

This code signifies a benign, localized bone disorder characterized by the replacement of normal bone with fibrous tissue and immature woven bone, specifically affecting a single bone in the left upper arm. This condition can lead to bone weakness, pain, and deformity.

Apply this code when documentation confirms a diagnosis of monostotic fibrous dysplasia, explicitly located in the left humerus or other bone of the left upper arm. Supporting documentation should include imaging reports (e.g., X-ray, MRI) and potentially biopsy results confirming the fibrous dysplastic changes.

• Ensure the documentation specifies "monostotic" and clearly identifies the left upper arm as the affected site.
• Differentiate from polyostotic fibrous dysplasia, which involves multiple bones and has different code assignments.
• Do not confuse with other bone lesions or tumors; pathology reports are crucial for definitive diagnosis.