Abstract
This case report highlights the importance of recognizing granulomatosis with polyangiitis (GPA) as a rare but potential cause of recurrent granulomatous mastitis and breast abscesses. The case report describes a patient who presented with recurrent breast abscesses over many years, initially misdiagnosed as infectious mastitis, until a breast tissue biopsy revealed granulomatous inflammation. Further evaluation confirmed the diagnosis of GPA based on elevated anti-neutrophil cytoplasmic antibodies (ANCA). The authors emphasize that, while breast involvement is exceedingly rare in GPA, it should be considered in cases of refractory granulomatous mastitis, even in the absence of typical systemic GPA manifestations. Early recognition can prevent misdiagnosis, allow timely initiation of immunosuppressive treatment, and avoid unnecessary procedures. The report calls for improved awareness and further research into the clinical characteristics and optimal management strategies for GPA presenting with breast lesions.