Intestinal endometriosis: Diagnostic ambiguities and surgical outcomes

BACKGROUND: Endometriosis is a common disease for women of reproductive age. However, when it involves intestines, it is difficult to diagnose preoperatively because its symptoms overlap with other diseases and the results of evaluations can be unspecific. Thus it is important to know the clinical characteristics of intestinal endometriosis and how to exactly diagnose. AIM: To analyze patients in whom intestinal endometriosis was diagnosed after surgical treatments, and to evaluate the clinical characteristics of preoperatively misdiagnosed cases. METHODS: We retrospectively reviewed the pathologic reports of 30 patients diagnosed as having intestinal endometriosis based on surgical specimens between January 2000 and December 2017. We reviewed their clinical characteristics and surgical outcomes. RESULTS: Twenty-three (76.6%) patients showed symptoms associated with endometriosis, with dysmenorrhea being the most common (n = 9, 30.0%). Thirteen patients (43.3%) had a history of pelvic surgeries. Ten patients (33.3%) had a history of treatment for endometriosis. Only 4 patients (13.3%) had a diagnosis of endometriosis based on endoscopic biopsy findings. According to preoperative evaluations, 13 patients (43.3%) had an initial diagnosis of pelvic endometriosis and 17 patients (56.6%) were misdiagnosed as having other diseases. The most common misdiagnosis was submucosal tumor in the large intestine (n = 8, 26.7%), followed by malignancies of the colon/rectum (n = 3, 10.0%) and ovary (n = 3, 10.0%). According to the Clavien-Dindo classification, 5 complications were grade I or II and 2 complications were grade IIIa. The median follow-up period was 26.9 (0.6-132.1) mo, and only 1 patient had a recurrence of endometriosis. CONCLUSION: Intestinal endometriosis is difficult to diagnose preoperatively because it mimics various intestinal diseases. Thus, if women of reproductive age have ambiguous symptoms and signs with nonspecific radiologic and/or endoscopic findings, intestinal endometriosis should be included in the differential diagnosis.