Osteitis deformans in neoplastic diseases, left ank/ft

This code signifies Paget's disease of bone occurring in the left ankle and foot, specifically when it is associated with a neoplastic process. It describes a localized bone remodeling disorder characterized by increased bone turnover and abnormal bone structure, complicated by the presence of a tumor.

Apply this code when documentation clearly indicates a diagnosis of Paget's disease affecting the left ankle and foot, and there is an explicit statement linking this condition to a co-occurring neoplasm. Supporting documentation would include pathology reports confirming Paget's disease and the neoplasm, as well as imaging studies detailing the affected anatomical site.

• Always code the underlying neoplasm first, followed by this code to indicate the manifestation.
• Ensure the documentation specifies "left" ankle and foot; laterality is crucial for accurate coding.
• Distinguish from Paget's disease without neoplastic involvement (M88.- series) or other forms of osteitis.