Endometriosis

Purpose: Inversion of the appendix can be seen incidentally at the time of colonoscopy and can be caused by a variety of factors. We present a case of an inverted appendix that was identified during a colonoscopy and that was due to endometriosis based on histologic examination after surgical resection. Methods: Case report. Results: A 51 year old woman with a history of endometriosis and menorrhagia presented for colonoscopy at the request of her primary care physician. She had a history of right lower quadrant pain. Surgical history included the removal of an endometrioma ten years prior and laparoscopic cholecystectomy five years prior to presentation. During colonoscopy, a smooth, soft, polypoid lesion was identified in the caput cecum. The lesion seemed to be extruding from the appendiceal orifice. Sigmoid diverticulosis was noted but the colonoscopy was otherwise unremarkable. A computed tomography scan revealed no abnormality in the pericecal region. A laparoscopic cecectomy was performed. At operation, the appendix was not clearly evident, but the mesoappendix appeared to be protruding into the caput cecum. Endometrial implants were not observed. When the specimen was examined, the appendix was inverted into the cecum. The histopathologic examination demonstrated endometriosis within the substance of the inverted appendix. This was supported by positive cytokeratin 7 and negative cytokeratin 20 staining. Conclusion: Most cases of inverted or intussuscepted appendix have been identified at the time of surgery. An inverted appendix may be caused by appendiceal carcinoma, carcinoid tumor of the appendix, mucocele, appendicitis, polyp or endometriosis. The condition may present with symptoms such as abdominal pain or may be asymptomatic. Although endometriosis of the appendix is well described, inversion of the appendix secondary to endometriosis is unusual and only 22 cases have been reported. Approximately 200 cases of appendiceal intussusception due to various causes have been described in the literature, and there are few cases of identification of an inverted appendix at the time of colonoscopy. The underlying etiology of an inverted appendix is typically established upon histologic examination of the surgical specimen as biopsies of the overlying mucosa and radiologic imaging of the region tend to yield non-diagnostic results. The development of a standardized approach to the evaluation of an inverted appendix found during colonoscopy would be helpful for clinicians.