Misdiagnosis of specific cytomegalovirus infection of the ileoanal pouch as refractory idiopathic chronic pouchitis: report of two cases.

PURPOSE: Chronic nonspecific reservoir ileitis (pouchitis) occurs in 5 to 10 percent of patients who undergo ileal pouch-anal anastomosis for ulcerative colitis. Specific infection of the ileal pouch-anal anastomosis with cytomegalovirus has not been reported. AIM: We report two patients with specific cytomegalovirus infection of the ileal pouch-anal anastomosis, initially misdiagnosed as idiopathic chronic pouchitis. CASE SERIES: Patient 1 had ileal pouch-anal anastomosis for ulcerative colitis. Three years later she had diarrhea, fever, pelvic pain, and pouch inflammation at endoscopy consistent with pouchitis. She had no response to medical therapy. Repeat endoscopy showed persistent inflammation and biopsies showed cytomegalovirus. She had symptomatic improvement after treatment with intravenous ganciclovir, 10 mg/kg/day for ten days (stopped for rash). Repeat pouch biopsies were negative for cytomegalovirus. Patient 2 had ileal pouch-anal anastomosis for ulcerative colitis. Nine years later she had resection of obstructing stricture at previous loop ileostomy site. She underwent reoperation with ileostomy and pouch defunctionalization for peritonitis. Four weeks later she had fever and bloody discharge from the diverted pouch. Pouch endoscopy with biopsy showed inflammation consistent with pouchitis. She had no response to medical therapy. Re-examination of pouch biopsies with a specific monoclonal immunofluorescent stain showed cytomegalovirus. She had symptomatic improvement after treatment with intravenous ganciclovir, 10 mg/kg/day for 21 days. Repeat pouch biopsies were negative for cytomegalovirus.
CONCLUSIONS: Specific cytomegalovirus infection of the ileal pouch-anal anastomosis may be misdiagnosed as idiopathic refractory chronic pouchitis. Cytomegalovirus must be excluded before immune modifier therapy or pouch excision in these patients.