A rare endoscopic appearance of granulomatosis with polyangiitis involving the intestine: a case report

BACKGROUND: The involvement of granulomatosis with polyangiitis is less frequent in the intestine. CASE PRESENTATION: We present a case of Wegener’s granulomatosis with unusual endoscopic appearance, involvement in a young man’s gastrointestinal tract. A 45-year-old man was diagnosed with Wegener’s granulomatosis 11 years ago, and relapsed with abdominal pain and melena. A colonoscopy was performed, and the appearance of mucosal lesions with an unusual annular black membrane was observed. A black ring-shaped membranous tissue adhered to the surface of the colon wall, which could be traversed by an endoscopic forepart. CONCLUSION: Biopsy of the black membrane revealed degenerative colonic mucosal tissues, while deep colonic biopsy revealed inflammatory granulation tissues. This has not been reported in previous documents.