Ectopic endometriosis, menstruation, and acute appendicitis: A thought-provoking case.

INTRODUCTION AND IMPORTANCE: Ectopic endometrium in the appendix is rare. The relationships between ectopic endometrium in the alimentary tract and digestive symptoms and between digestive symptoms due to ectopic endometriosis and periodic menstruation are controversial. We herein describe the successful treatment of acute appendicitis that we suspect was caused by ectopic endometriosis and periodic menstruation. PRESENTATION OF CASE: A 38.9-year-old multipara with uterine didelphys developed lower abdominal pain during menstruation, and she was clinically diagnosed with acute appendicitis. She received conservative management with cephem antibiotics, and her pain disappeared uneventfully. However, the lower abdominal pain during menstruation later recurred, and she again received conservative treatment. Laparoscopic appendectomy was subsequently performed because for 4 months, her appendicitis-induced digestive symptoms had recurred in association with periodic menstruation. Ectopic endometrial gland proliferations were histopathologically observed in the proper muscular layer of the appendiceal tip. She developed no further episodes of digestive symptoms postoperatively. CLINICAL DISCUSSION: Ectopic endometriosis of the alimentary tract may be accompanied by digestive symptoms; moreover, these symptoms may be related to periodic menstruation. However, the sensitivity of ectopic endometrium to hormones shows considerable variation among patients. We speculate that the acute appendicitis might have been triggered by ectopic endometriosis in our case because the patient developed repeated digestive symptoms in association with periodic menstruation. Ectopic endometrium may be incidentally observed in histopathological assessments of resected specimens. The therapeutic strategy should be carefully decided on a case-by-case basis. CONCLUSION: We hope this thought-provoking case provides a timely reminder for gastrointestinal clinicians and general surgeons.