Granulomatous Polyangiitis (GPA) is a rare form of small vessel vasculitis characterized by the demonstration of necrotizing granulomatous inflammation histologically.
We report the case of a 62-years-old woman with symptoms of cough and significant loss of weight with radiological findings to support a left lower lobe lung mass. The patient was initially suspected to have metastatic lung malignancy until biopsy results suggested necrotizing granulomatous inflammation. A diagnosis of limited GPA was made when the cytoplasmic antineutrophil cytoplasmic antibodies, (c-ANCA) and antiproteinase-3 antibodies (anti-PR3) was elevated. The patient was treated with combination therapy of prenisolone (1 mg/kg) and methotrexate which induced clinical remission within weeks and radiological complete remission within 3 months.
However, as prednisolone was tapered down, there were suggestions of a relapse. Conclusion: The presentation of GPA can be highly variable and pose a diagnostic challenge to clinicians. In cases at risk for relapse, treatment should be continued for at least 18-24 months.