Granulomatosis with polyangiitis (GPA) is characterized by necrotizing granulomatous lesions and is classified as ANCA-associated vasculitis (AAV). We herein report a case of GPA that was remitted by resection of a pulmonary lesion without immunosuppressive therapy. We detected activated neutrophils and neutrophil extracellular traps (NET) formation in resected lung tissue by immunofluorescence. Activated neutrophils and NETs might be involved in the pathophysiology of AAV and induce the vicious cycle of ANCAs and NETs. In cases of GPA with no other severe lesions, the reevaluation of the disease activity after diagnostic resection is crucial for considering the need for immunosuppressive therapy.