ANCA-associated vasculitis complicated by haemoperitoneum

We present a case of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis with the rare complication of haemoperitoneum due to mesenteric vessel involvement. Initial investigations demonstrated typical renal features including haematoproteinuria and a focal segmental necrotising glomerulonephritis. The patient then developed haemoperitoneum and required an emergency hemicolectomy. Subsequent histology revealed ileo-colic arteritis with aneurysm formation and rupture. A sustained remission was achieved with corticosteroids and mycophenolate mofetil followed by azathioprine. This case demonstrates the need for a high degree of vigilance in patients with ANCA-associated vasculitis who develop abdominal symptoms.