Appendiceal intussusception mistaken for a polyp at colonoscopy: case report and review of literature

Abstract

Ann R Coll Surg Engl 2010; 92:1 Intussusception of the vermiform appendix is a rare condition, with an approximate incidence of 0.01%. It can mimic several clinical conditions including acute appendicitis or be mistaken as a caecal polypoid lesion on radiological imaging and endoscopy. Correct diagnosis is paramount in order to prevent unnecessary and potentially catastrophic interventions such as endoscopic excision. Despite the availability of various investigative modalities including barium enema, transabdominal ultrasound, computed tomography (CT) colonogram and colonoscopy, 1,2 the diagnostic accuracy remains poor. We report a case of appendiceal intussusception which was erroneously labelled as a 10-mm polypoid caecal lesion on colonoscopy and, therefore, followed up over an 11-year period before the correct diagnosis was made. We present the radiological and endoscopic appearance of appendiceal intussusception and a review of the literature. Case historyA 49-year-old Caucasian woman with a strong family history of colon cancer presented to the colorectal clinic in 1997 with a several year history of constipation and mild abdominal pain. A barium enema showed a long and tortuous colon with a polypoid lesion in the caecum. A subsequent colonoscopy was technically challenging but successful and confirmed the presence of a 10-mm 'polypoid lesion' in the caecum. Multiple biopsies were taken and showed normal colonic mucosa.Because of doubt about its nature and in view of the difficulties met on previous colonoscopy, this lesion was followed up with serial barium enemas. It remained unchanged until 2008, when a fourth barium enema showed an increment in size and in fact a subsequent CT colonogram confirmed the lesion to be 18.2 mm at its base and 11.1 mm in anteroposterior depth (Fig. 1). A second colonoscopy was, therefore, performed with a view to endoscopic excision. However, on this occasion, the lesion was recognised as an intussuscepted appendix and multiple biopsies confirmed normal colonic mucosa (Fig. 2). The diagnosis become more obvious as the We report a case of appendiceal intussusception which was erroneously labelled as a 10-mm polypoid caecal lesion on colonoscopy and, therefore, followed up over an 11-year period before the correct diagnosis was made. We present the radiological and endoscopic appearance of appendiceal intussusception and a review of the literature. ON-LINE CASE REPORT

Intussusception of the Appendix and Ileum Endometriosis: A Case Report

“…The intussusception of the appendix may lessen during colonoscopy, when air is insufflated [17], or there may even be a total reduction of it [4]. If the intussusception of the appendix has been reduced during the colonoscopy, a central depression at the base of the cecum corresponding to the appendiceal lumen surrounded by an area with an erythematous halo can be seen [1].…”

“…In our case, laparotomy and ileocecal segment resection was performed in order to remove the appendix and the tumor (which was an endometrial implant) in the terminal ileum. Naturally, in the case of patients with long-standing asymptomatic appendiceal intussusceptions, some authors suggest to avoid a surgical intervention [17]. However, this pathology is too rare, and there are no reliable data for evaluating the risk of complications in the natural course of an appendiceal intussusception.…”

Appendiceal Intussusception

“…Type IV refers to complete inversion of the appendix with accompanying ileocaecal intussusception, whereby the appendix remains the leading point of the intussusceptum. This can result from types I and II of appendiceal intussusception (Salehzadeh et al, 2010). Finally, Jacobs in 1963 argued that the term "intussusception of the appendix" should be reserved only for the condition in which the appendix intussuscepts into itself, in the same way that ileum intussuscepts into ileum in the ileo-ileal type of intussusception.…”

“…Endoscopical removal of this lesion is associated with a high risk of subsequent peritonitis (Khawaja, 2002). Visualization of an appendiceal intussusception as a caecal polyp could also be achieved by means of CT colonogram scanning (Salehzadeh et al, 2010) …”

The inverted appendix – a potentially problematic diagnosis: clinicopathologic analysis of 21 cases

“…The condition affects predominantly adult women, most commonly in the fourth decade . The underlying pathophysiology is thought to involve abnormal peristalsis secondary to irritation, as well as predisposing anatomical factors, including a mobile mesoappendix, a large appendiceal orifice, and underlying masses in some cases . Many associated pathological findings have been described in the literature, including endometriosis, adenomas, adenocarcinoma, and mucinous neoplasms …”