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

This code signifies a primary cancerous tumor that originates in and spans across multiple adjacent bone and/or articular cartilage sites within the left upper or lower limb. This indicates the malignancy is not confined to a single bone or joint but involves overlapping anatomical regions.

Use this code when diagnostic imaging (e.g., MRI, CT scan) and/or biopsy confirm a primary malignant neoplasm affecting contiguous bone and cartilage structures of the left arm or leg. Documentation should clearly specify the left limb and the involvement of multiple, overlapping sites.

• Ensure the documentation explicitly states "overlapping sites" and specifies the "left limb" to support this code.
• Distinguish from C40.0-C40.3, which specify single bone sites within a limb.
• Always code the specific primary site(s) if the neoplasm is not described as overlapping.