[ANCA-negative granulomatosis with polyangiitis: a case report]

Area of Science:

• Pulmonology
• Rheumatology
• Pathology

Background:

• Necrotizing granulomatous polyangiitis (NGP) is a rare systemic vasculitis.
• Pulmonary involvement with nodules and cavities can mimic infections or malignancies.
• Distinguishing NGP, especially ANCA-negative forms, is diagnostically challenging.

Observation:

• A 73-year-old male presented with progressive dry cough, shortness of breath, multiple pulmonary nodules, and cavities.
• Initial treatments for infection and tuberculosis were ineffective, with disease progression.
• Laboratory tests revealed anemia and renal dysfunction; anti-neutrophil cytoplasmic antibodies (ANCA) were negative.

Findings:

• Bronchoscopic biopsy demonstrated granulomatous inflammation, vasculitis, and necrosis within pulmonary lesions.
• Histopathological findings, coupled with clinical presentation and negative ANCA, led to a diagnosis of ANCA-negative NGP.
• Treatment with glucocorticoids and cyclophosphamide resulted in shrinkage and absorption of pulmonary nodules and cavities.

Implications:

• This case underscores the importance of considering ANCA-negative NGP in patients with unexplained pulmonary nodules and cavities.
• Early diagnosis and immunosuppressive treatment are crucial for managing this rare vasculitis.
• Further research into diagnostic markers and optimal treatment strategies for ANCA-negative NGP is warranted.