Malig neoplm of ovrlp sites of bone/artic cartl of unsp limb

This code signifies a cancerous tumor that spans across multiple adjacent anatomical regions within the bone and articular cartilage of an unspecified limb. This indicates a primary malignancy originating in or extending to involve more than one site, such as the distal femur and proximal tibia, where the exact limb (e.g., right or left) is not documented.

Apply this code when documentation clearly indicates a primary malignant neoplasm affecting overlapping sites of bone and articular cartilage, and the specific limb involved is not specified. This is appropriate for initial diagnoses or follow-up care where the laterality of the limb remains undetermined in the medical record.

• Do not use this code if the specific limb (right or left) is documented; instead, select a more specific code from the C40.8- series.
• Ensure the documentation explicitly states "overlapping sites" or describes a tumor spanning multiple contiguous bone and articular cartilage areas.
• This code is for primary malignancies; use secondary neoplasm codes (C79.-) if the tumor is metastatic to these sites.