Penetrating colon ulcer of polyarteritis nodosa: report of a case.

A 54-year-old Japanese female with polyarteritis nodosa was admitted to the hospital. She developed lower abdominal pain accompanied by melena. A penetrating ulcer and extensive hemorrhaging were endoscopically observed in the sigmoid colon, and a sigmoidectomy was performed. The pathologic findings were a granuloma formation with lymphocytic infiltration and luminal occlusion of branches of the mesenteric arteries. Although the gastrointestinal tract is frequently involved in polyarteritis nodosa, the colon is rarely affected. To our knowledge, this is the first report of polyarteritis nodosa causing a penetrating ulcer of the colon.