Aneurysmal bone cyst, left upper arm

This code signifies a benign, blood-filled lesion within the bone of the patient's left upper arm. It is characterized by cystic spaces separated by fibrous septa and is typically expansile, potentially causing pain or swelling.

Assign this code when documentation confirms a diagnosis of aneurysmal bone cyst specifically located in the left humerus or other bone of the left upper arm. Supporting documentation would include imaging reports (X-ray, MRI) and/or pathology reports confirming the diagnosis and precise anatomical location.

• Ensure laterality is clearly documented as "left upper arm" to justify this specific code.
• Distinguish from other benign bone tumors or cysts; a definitive diagnosis of aneurysmal bone cyst is required.
• Do not use for other anatomical sites or if the cyst is not definitively identified as aneurysmal.