Secondary malignant neoplasm of bone

This code signifies the presence of a malignant tumor in the bone that originated from a primary cancer elsewhere in the body. It indicates that cancer cells have metastasized to the skeletal system, forming a secondary growth.

Apply this code when documentation clearly states a diagnosis of metastatic cancer to the bone. This is typically used in patients with a known history of a primary malignancy who subsequently develop bone involvement. Supporting documentation includes pathology reports confirming metastatic disease in bone, imaging studies showing bone lesions consistent with metastasis, and physician notes explicitly stating "secondary malignant neoplasm of bone" or "bone metastasis."

• Always sequence the primary malignancy code before this code, unless the primary site is unknown or has been excised and is no longer being treated.
• Do not use this code for primary bone cancers (e.g., osteosarcoma); those have specific codes in the C40-C41 range.
• Ensure the documentation specifies "secondary" or "metastatic" to the bone to differentiate from primary bone neoplasms.