A challenging case of granulomatosis with polyangiitis with cardiac involvement: a rare case report.

Background: Granulomatosis with polyangiitis (GPA), a systemic antineutrophil cytoplasmic antibody (ANCA) associated vasculitis, is characterized by inflammation of the small arteries, arterioles, and capillaries classically manifesting with glomerulonephritis and necrotizing granulomatous lesions of the upper and lower respiratory tract. With an incidence of approximately 12 cases per one million individuals per year it is an uncommon diagnosis that typically presents as frequent pulmonary and sinus infections; however, if left without definitive treatment progresses to more severe manifestations specifically hemoptysis and hematuria. Case Description: This case report highlights a 15-year-old woman who had both classic and non-classic findings making the diagnosis challenging. Specifically, her age of presentation, improvement with anti-microbials, and coronary dilation were not classic. Additionally, her lab work was negative for the cytoplasmic subset antineutrophil cytoplasmic autoantibody (c-ANCA), but positive for serum anti-proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA) which further delayed the ultimate diagnosis as this is typically c-ANCA positive. Conclusions: Other systemic vasculitides, such as mucocutaneous lymph node disease, are associated with cardiac pathology necessitating further medical management and follow-up to prevent increased morbidity and mortality. Knowing this, we conclude that further evaluation for cardiac pathology would be prudent as part of the initial workup of patients with a diagnosis of GPA. Included is a brief review of available literature on GPA to emphasize the typical presentation, lab findings, and importance of early diagnosis.