Hemoperitoneum in a patient with ANCA-associated polyangiitis syndrome.

Antineutrophil cytoplasmic antibody-associated vasculitides often cause small-vessel vasculitis, usually involving the kidney. Involvement of other organ systems and medium to large arteries is recognized, but free-vessel rupture is rare. A case of a man with classic renal involvement caused by microscopic polyangiitis associated with multiple episodes of hemoperitoneum secondary to splanchnic vasculitis is described. Although his renal vasculitis responded to conventional immunosuppressive treatment, relentless progression of splanchnic vasculitis ultimately proved fatal.