Isolated granulomatous pulmonary artery vasculitis associated with Hughes-Stovin Syndrome: a case report

Abstract Background Hughes-Stovin Syndrome (HSS) in an exceptionally rare vasculitis, characterised by pulmonary artery aneurysms (PAAs) with in-situ thrombosis and is increasingly regarded as part of the vascular Behcet spectrum. Diagnosis remains challenging due to its rarity, lack of validated diagnostic criteria and overlap with other vasculitis. Case Summary We describe a 71 year old male who presented with progressive dyspnoea and chest pain. Serial imaging demonstrated rapid enlargement of a main pulmonary artery aneurysm from 5mm to 68x55mm over 18 months, prompting surgical repair. Histopathological examination of the resected pulmonary artery demonstrated granulomatous arteritis with multinucleated giant cells, transmural inflammation and disruption of the elastic lamina, confirming isolated of pulmonary artery vasculitis. In the context of pulmonary artery aneurysm, normal coagulation studies and systemic exclusion of alternative causes including Behcet disease, giant cell arteritis, Takayasu arteritis, infection and malignancy, the findings were considered most consistent with Hughes-Stovin’s syndrome. Following multidisciplinary review, immunosuppression was commenced with corticosteroid and Methotrexate before transition to Tocilizumab and Mycophenolate Mofetil. Recurrent pulmonary thrombosis despite therapeutic Apixaban required conversion to therapeutic Enoxaparin. At latest follow up, the patient remained clinically stable with no evidence of active vasculitis or recurrent aneurysm. Conclusion This case highlights a rare presentation of isolated granulomatous pulmonary artery vasculitis associated with Hughes-Stovin syndrome in an older patient. The case demonstrates the importance of cautious diagnostic classification and exclusion of alternative diagnosis through serial multimodal imaging, timely surgical intervention, prompt commencement of immunosuppression and multidisciplinary care.