Intussusception of the Appendix Associated With Endometriosis

Appendiceal endometriosis representing the lead point for appendiceal intussusception is rare with fewer than 30 cases reported in the past 50 years. This is the case of a 51-year old female who presented with several months of intermittent, worsening right lower quadrant abdominal pain. Colonoscopy found an appendiceal polyp in an inverted appendix, with subsequent removal of the polyp. Laparoscopic appendectomy with pathology of the appendix showed endometriosis. This case serves to broaden clinician knowledge of a rare phenomenon that presents with the common complaint of abdominal pain. The patient is a 51-year old post-menopausal female who presented to a clinic with several months of worsening right lower quadrant pain and pressure. A colonoscopy was conducted with findings of a single hyperplastic polyp located within the appendix with subsequent polypectomy. The polyp is shown in Figure 1. Follow up computed tomography (CT) scan of the abdomen showing a curvilinear soft tissue mass within the cecum consistent with an inverted appendix. This image is seen in Figure 2. A cecectomy was performed with additional resection of the appendix. Pathology of the appendix showed endometriosis with benign glandular proliferation within normal appendiceal tissue. This is seen in Figure 3. After surgery, the patient initially had minimal pain with eating and moving her bowels with eventual improvement. Endometriosis is the presence of endometrial glands and stroma outside the uterine cavity and is estimated to affect 4%-50% of reproductive aged women. Endometriosis presenting as a lead point for appendiceal intussusception is rare with fewer than 30 cases presented in the literature over the past 50 years. Endometriosis of the appendix can present with cyclic abdominal pain in the right lower quadrant and mimic findings of appendicitis. Imaging can show a target-like lesion with concentric rings of intussuscepted appendiceal tissue. Our patient's CT imaging is shown in Figure 2. Definitive diagnosis is through histopathologic examination after biopsy or resection of the affected tissue and is seen in Figure 3. Our patient underwent a cecectomy with removal of the appendix. This case report adds to the limited literature on endometriosis as a possible lead point for appendiceal intussusception. It also seeks to sharpen the clinician's diagnostic capabilities by highlighting a rare disease that may be the cause of the common complaint of abdominal pain.1463_A Figure 1. Inverted appendix on endoscopy1463_B Figure 2. Inverted appendix appreciated on CT scan1463_C Figure 3. Glandular tissue in the stroma representing endometriosis with normal appendix tissue in the bottom right of the image