Polyarteritis nodosa of the descending colon. Case report.

: A 28-year-old man presented with fulminant, haemorrhagic, left-sided colitis, that was thought to be Crohn's disease both clinically and macroscopically. Histopathological examination, however, showed polyarteritis nodosa. The patient had no other signs of this disease, which should be added to the differential diagnoses of colitis.