Intestinal Endometriosis: Mimicker of Inflammatory Bowel Disease?

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.

One hundred consecutive, unselected cases of surgically resected IE were collected and clinical features and histopathology reviewed and reevaluated.

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.

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.