Metastatic Breast Cancer and Granulomatosis with Polyangiitis

Introduction: Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis, which includes granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), are life-threatening vasculitis. Several studies reported that up to 8% of patients with a malignant disease had ANCA-associated vasculitis. Sixty three percent of malignancies associated with vasculitides, were hematologic in origin. In this report, we describe a rare case of a recurrent breast cancer and GPA in the same lung lesion. Case Report: A 66-year-old woman with a past medical history of scleroderma, inflammatory lung disease, and remote bilateral breast cancer status post bilateral mastectomy and chemotherapy was admitted for lung biopsy. The patient developed flu-like symptoms and was started on oral antibiotics after she was seen in an urgent care clinic. Despite this, she developed worsening dyspnea and hemoptysis. Her outpatient CT chest showed multiple lung cavities with bilateral fibrotic changes. Her initial blood test was positive for anti-neutrophil cytoplasmic antibodies (ANCA), anti-cyclic citrullinated peptide antibodies (CCP), and rheumatoid factor (RF). Because of this, she was admitted for a lung biopsy as a workup for vasculitis disease. Initially, the patient was isolated in a room with negative pressure to rule out tuberculosis (TB). Her QuantiFERON TB test and acid fast bacilli smears were negative. Later, a thoracic surgery team was consulted to perform lung biopsy through video-assisted thoracoscopic surgery (VATS). Her lung biopsy revealed metastatic breast cancer that was positive for estrogen receptor, and a necrotizing granulomatous inflammation that was consistent with granulomatosis with polyangiitis (GPA) formerly known as Wegener \u27s disease. The oncology team recommended to start her on anastrozole as a treatment for breast cancer. The rheumatology team recommended a loading dose of intravascular methylprednisone and then a maintenance dose of oral prednisone. A permacath was placed in order to start outpatient rituximab infusion as a treatment for vasculitis. In addition, she was started on trimethoprim-sulfamethoxazole for pneumocystis pneumonia prophylaxis and advised to continued her home dose of mycophenolate mofetile for treatment of scleroderma. Discussion: There are two forms of vasculitis: primary and secondary. Secondary vasculitis has been linked to several processes, such as medications side effect, allergic reaction, rheumatologic and neoplastic disease. A close relationship between the diagnosis of malignancy and onset of vasculitis has been reported in a number of patients. Most vasculitides were cutaneous leukocytoclastic (45%) and polyarteritis nodosa (36%). The exact pathogenesis of malignancy-associated vasculitis is unclear. However, we hypothesize that the inflammatory responses provoked by the underlying neoplasm might contribute to the pathogenesis. To the best of our knowledge, this is the first case report of recurrent breast cancer and development of GPA that may be representative of an association between the two condition. Clinicians must be aware of associations between various medical conditions as it most certainly changes the management. While we do not dispute that, our case may be just a co incidence of two medical conditions at once, we believe a very low incidence of GPA deserve a second look in finding an association with other medical conditions should one be present