Abstract Background Granulomatosis with polyangiitis (GPA) previously known as Wegener's granulomatosis is a rare complex immune-mediated disease and a multisystem disorder with varying presentations where many of the imaging features of GPA overlap with those of other diseases, and hence its diagnosis can be challenging. Case presentation Here we report a case of a 48-year-old female who presented with complaints of hemoptysis, difficulty in speech, bilateral progressive hearing loss and, a palpable lump in the right breast. The case was initially misdiagnosed as breast carcinoma but biopsy proved to be GPA. Here we present the multisystem manifestations of GPA involving the head and neck, breast, lungs, spleen with involvement of the breast being very rare. The breast lesion showed improvement with steroids on follow-up. Conclusions GPA is a multisystem disease and though breast lesions in GPA are rare, a thorough knowledge about this uncommon manifestation is required and clinical, radiological, and histopathological correlation is of utmost importance in the evaluation of a breast lesion in cases of multisystem involvement to avoid unnecessary surgeries. The differential diagnosis of breast tumors should include such rare conditions that can sometimes mimic breast cancer. Early diagnosis and initiation of the immunosuppressive treatment help in a better prognosis of the disease.
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