title: Microscopic polyangiitis complicated with ileal involvement detected by double-balloon endoscopy: a case report.
abstract: BACKGROUND
  Microscopic polyangiitis is characterized by pauci-immune, necrotizing small-vessel vasculitis and an anti-neutrophil cytoplasmic antibody-associated vasculitis. Although gastrointestinal involvement in microscopic polyangiitis is not rare, endoscopic observation of it is extremely rare. To the best of our knowledge, this is the first case report of small intestinal involvement in microscopic polyangiitis detected and followed up by double-balloon endoscopy.
  
  
  METHODS
  A 70-year-old Japanese woman was transferred to our hospital for close examination of suspected small intestinal lymphoma. Retrograde double-balloon endoscopy revealed various forms of ulcers with redness and edema in the ileum. Histological findings suggested ischemic changes. Because mononeuritis multiplex and a fever spike appeared later, vasculitis was suspected. The perinuclear anti-neutrophil cytoplasmic antibody titer was elevated. Nerve biopsy results suggested vasculitis. From these findings, microscopic polyangiitis was diagnosed. It was suggested that microscopic polyangiitis caused the intestinal involvement. Intravenous pulse cyclophosphamide and oral predonisolone were started. After treatment, perinuclear anti-neutrophil cytoplasmic antibodies decreased to the normal range. Retrograde double-balloon endoscopy after treatment showed ulcer scars and no ulcer.
  
  
  CONCLUSIONS
  The cause of gastrointestinal involvement in microscopic polyangiitis is ischemia due to vasculitis. It is difficult to diagnose small-vessel vasculitis by endoscopic biopsy. Although histological evidence of microscopic polyangiitis is important, the treatment should not be delayed by repeating the biopsy, because such delay can result in adverse sequela.This case report shows that microscopic polyangiitis should be considered as a differential diagnosis when small intestinal changes like those in the present case are observed by endoscopy.
authors: Department of Gastroenterology, Kobe City Medical Center General Hospital, 2-1-1 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan. mfuku4585@hotmail.com
authors: Masashi
authors: M
authors: Fukushima
authors: Satoko
authors: S
authors: Inoue
authors: Yuichiro
authors: Y
authors: Ono
authors: Yoshitaka
authors: Y
authors: Tamaki
authors: Hajime
authors: H
authors: Yoshimura
authors: Yukihiro
authors: Y
authors: Imai
authors: Tetsuro
authors: T
authors: Inokuma
mesh_terms: D000368:Aged; D003520:Cyclophosphamide / Q000627:therapeutic use; D004487:Edema / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D016099:Endoscopy, Gastrointestinal / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007077:Ileal Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D055953:Microscopic Polyangiitis / Q000150:complications*; D011239:Prednisolone / Q000627:therapeutic use; D016896:Treatment Outcome; D014456:Ulcer / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*
chemical_list: D003520:Cyclophosphamide; D011239:Prednisolone