Aneurysmal bone cyst, left thigh

This code represents an aneurysmal bone cyst (ABC), a benign, expansile, osteolytic bone lesion characterized by blood-filled spaces, specifically located in the left thigh. It is a non-neoplastic lesion that can cause pain, swelling, and pathological fractures.

Use this code when documentation clearly identifies an aneurysmal bone cyst affecting the left femur or other bones of the left thigh. Supporting documentation typically includes imaging reports (X-ray, MRI) confirming the diagnosis and location, and/or pathology reports from biopsy.

• Ensure the laterality is precisely documented as "left" and the anatomical site is "thigh."
• Differentiate from other benign bone tumors or cysts; documentation must specify "aneurysmal bone cyst."
• If a pathological fracture is present due to the cyst, an additional code for the fracture should be sequenced first, followed by this code.