Two Cases of Appendiceal Intussusception: A Rare Diagnostic Pitfall in Colonoscopy

Partially or completely invaginated appendix mistaken for a polyp during colonoscopy and leading to intussusception is a rare situation. This paper describes our experience with two cases of appendiceal intussusception. In the first case, there was no underlying ileocecal abnormality, and, in the second case, histologic examination of the resected appendix and cecum revealed widespread foci of angiodysplasia, and this was thought to be the basis for the intussusception. The authors present reviews of the literature concerning clinical features and associated conditions and emphasize that failure to recognize this condition may result in unexpected complications such as consequent peritonitis in case of endoscopic removal. 1. Introduction Intussusception of the appendix is an extremely rare condition. It affects all ages but is usually associated with males in the first decade [1]. Despite its rarity, endoscopists must consider appendiceal intussusception in the differential diagnosis when a “polyp” is seen on colonoscopy in order to avoid a consequent peritonitis in case of endoscopic removal. We report here two cases: the first was fortuitously discovered on colonoscopy, and the second was responsible for lower- gastrointestinal-tract bleeding. We insist on morphological characteristics as to permit an early recognition and treatment of this condition. 2. Case Report 2.1. Case 1 A 48-year-old man with several years history of abdominal pain and transit disturbances was admitted to our hospital for further investigations. Physical examination and laboratory data were within normal limits. Colonoscopy revealed a sessile, dimpled 20？mm cecal polyp (Figure 1) covered with macroscopically normal colonic mucosa. The appendiceal orifice in the cecum was not seen. Biopsies were performed, and, 12 hours after, the patient experienced fever and shivering. Clinical examination of the abdomen and plain abdominal roentgenogram were normal. Complete recovery was obtained after broad spectrum antibiotherapy. On histology, the polyp was found to be normal inverted appendiceal wall. Abdominal ultrasound and CT scan showed a partially invaginated appendix into the cecal cavity without any evidence of tumoral process. Regular ultrasound examinations during two years showed an unchanged aspect of the inverted appendix Figure 1: Sessile, dimpled 20？mm polypoid mass in the cecum. Colonoscopic image. 2.2. Case 2 A 65-year-old man was admitted to our hospital with a six-month history of melena with transfusion requirement. Hemogram showed hypochromic microcytic anemia