B35-33 Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis After Lung Resection: Implications of Postoperative Inflammation

Introduction Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of autoimmune disorders characterized by inflammation of small to medium sized blood vessels. Typically, ANCA vasculitis presents idiopathically with manifestations of multisystem disease. Lung manifestations of ANCA associated vasculitis often include necrotizing granulomatous inflammation and tracheobronchial inflammation. It is rarely reported that ANCA vasculitis presents secondarily after an inflammatory insult. Here we report a case of new onset ANCA vasculitis in a patient with no clinical history after lung resection. Case description A 67 year old female with a past medical history of adenocarcinoma of the lung presented to the pulmonary clinic for evaluation of abnormal chest imaging. The patient initially underwent wedge resection 3 years prior with successful removal of adenocarcinoma in situ. On follow up CT scan 1 year later, large lesions at the surgical site was noted. Biopsies of the lesions were performed and showed necrotizing cavitary granulomatous inflammation. Tissue cultures were negative for organisms and cytology was negative for malignancy. Serologic allergic antibody testing for metals was negative. A right upper lobectomy was performed 6 months later due to worsened cavitation. Pathology from the lung resection showed continued necrotizing granulomas, lymphoid aggregates, and necro-inflammatory debris. Multidisciplinary discussion prompted autoimmune testing, for which she was found to be cytoplastic-ANCA positive with positive proteinase-3 antibody. Given concern for ANCA vasculitis, the patient was started on prednisone. After the initiation of steroid treatment, she had significant radiologic improvement of her disease and she was started for mycophenolate mofetil for maintenance of remission. Discussion New onset ANCA vasculitis after a surgical procedure is extremely rare. Granulomatous inflammation in this case was carefully examined for other causes such as infection, malignancy, or allergic response. With negative testing for these conditions, positive testing for ANCA antibodies, and clinical response to induction therapy, we reached a multidisciplinary conclusion of new onset granulomatosis with polyangiitis. This condition usually arises idiopathically with typical manifestations of pulmonary, renal, and upper airway disease. Treatment typically requires both induction therapy and maintenance of remission once clinical response is made. More research is needed for the association of inflammation to the direct cause of ANCA vasculitis, as this is the first case report noting wedge resection and lobectomy as the inciting event.