[Ileal endometriosis and Crohn's disease. A difficult differential diagnosis]

Endometriosis is an endometrial tissue proliferation that occurs in any extrauterine site and is usually confined to the pelvis. When the terminal ileum is affected, this entity can simulate Crohn's disease both clinically and radiologically. We describe 2 patients previously diagnosed with Crohn's disease with inadequate response to treatment, who showed intestinal obstruction located in the ileum. One patient had an enterocutaneous fistula, which is extremely unusual. In both patients intestinal endometriosis was diagnosed after histopathologic assessment. Although complex, the differential diagnosis between endometriosis and Crohn's disease should be kept in mind since the prognosis and treatment of these 2 entities differ.