Antineutrophilic cytoplasmic antibody [ANCA] vasculitis

This code represents vasculitis characterized by the presence of antineutrophilic cytoplasmic antibodies (ANCAs), which target proteins within neutrophils. This autoimmune condition causes inflammation and damage to small and medium-sized blood vessels, potentially affecting multiple organ systems.

Use this code when documentation explicitly states a diagnosis of ANCA vasculitis, without further specification of a particular ANCA-associated vasculitis subtype. This diagnosis is typically confirmed by positive ANCA serology and biopsy findings consistent with vasculitis.

• Ensure documentation clearly states "ANCA vasculitis" or a similar general term, rather than a specific subtype.
• Review "Excludes2" notes carefully to avoid miscoding specific ANCA-associated vasculitides like GPA, EGPA, or MPA.
• Code any associated organ manifestations (e.g., glomerulonephritis, pulmonary hemorrhage) separately.