Osteitis deformans in neoplastic diseases, multiple sites

This diagnosis code signifies Paget's disease of bone (osteitis deformans) that is occurring secondary to or in conjunction with a neoplastic process, affecting multiple skeletal sites. It describes a metabolic bone disorder characterized by abnormal bone remodeling, presenting in a patient with cancer, and involving more than one bone.

Use this code when documentation clearly indicates a diagnosis of Paget's disease of bone that is directly associated with a neoplastic condition, and the disease manifests in multiple locations throughout the skeleton. The medical record should specify both the neoplastic disease and the widespread nature of the osteitis deformans.

• Always code the underlying neoplastic disease first, as this code represents a manifestation or complication of the cancer.
• Ensure documentation specifies "multiple sites" for the osteitis deformans; otherwise, a site-specific code for Paget's disease might be more appropriate.
• Distinguish from Paget's disease of bone not associated with a neoplastic process (M88.- codes) or Paget's disease of bone with malignant degeneration (M89.81- codes).