Intestinal Endometriosis: Mimicker of Inflammatory Bowel Disease?

Background/Aims: Endometriosis of the intestinal tract (IE) is thought to mimic inflammatory bowel disease (IBD) both clinically and pathologically but robust data on a large unselected series are missing. Diagnostic problems arise both at colonoscopy as well as on resection specimens for IE when IBD-like features are encountered. The aim was to establish the frequency of IBD-like histology in IE and which type of histological lesions are shared by these two entities. Methods: One hundred consecutive, unselected cases of surgically resected IE were collected and clinical features and histopathology reviewed and reevaluated. Results: Seventy-five surgical specimens showed no histological alterations except for endometriosis foci. Twenty-two cases showed focal architectural alterations in the absence of significant inflammation. Three cases showed marked inflammatory and architectural mucosal changes making a differential diagnosis with IBD particularly challenging. On follow-up, however, these patients remained symptom-free and with no need for anti-inflammatory therapy after surgical resection of IE. Conclusions: Diagnostic problems may arise in women who have IBD-like symptoms and histology at colonoscopy but who lack a known diagnosis of endometriosis. Clinicians must be aware that the diagnosis of IBD in patients with IE should be reevaluated over time.