Mediastinal-Renal Syndrome: A Rare Manifestation of Granulomatosis with Polyangiitis

Granulomatosis with polyangiitis (GPA) is a distinct systemic disorder of obscure etiology characterized by necrotizing granulomatous inflammation and pauci-immune small-vessel vasculitis. Anti-neutrophil cytoplasmic antibodies (ANCA) appear to play an important role in the pathogenesis of GPA. Herein, we report a rare case of GPA presenting with ANCA-associated pauci-immune necrotizing and crescentic glomerulonephritis accompanied by a mediastinal mass and mediastinal lymphadenopathy in the absence of pulmonary parenchymal involvement. Furthermore, we describe the effects of plasmapheresis and concomitant immunosuppression on renal and mediastinal disease.