Atypical endoscopic finding of colocolic intussusception: case report and literature review.

Background: Adult-onset colonic intussusception is a rarely encountered condition that leads to large intestinal obstruction with time. Patients often present with a variety of symptoms that are non-specific making it challenging to arrive at a definitive diagnosis. This is worrying as diagnostic delay could lead to a significant increase in morbidity and mortality. We wish to present and describe a case of an atypical endoscopic finding of colocolic intussusception secondary to ascending colon cancer. Case Description: Sixty-seven-year-old lady was referred for 1 month's duration of passing melenic stools with mucus followed by a week's complain of hematochezia. Clinical examination and other relevant blood results were unremarkable except for iron deficiency anemia. Initial colonoscopy revealed a large mass within the splenic flexure with inconclusive biopsies. A more detailed colonoscopy repeated the following day revealed a massive, black-to-yellowish lesion within the splenic flexure with no viable mucosa seen. Colonic bezoar was initially suspected, however various endoscopic retrieval methods proved futile. Switching to a slimmer diagnostic gastroscope, the colon was carefully negotiated until a large ulcer was found within the ascending colon, adjacent to the mass' origin. An emergency CT abdomen and subsequently extended right hemicolectomy performed revealed a colocolic intussusception with sealed perforation secondary to an ascending colonic mass acting as an intussusceptum. Histopathology evaluation confirmed an ascending colon adenocarcinoma (pT2N0M0) amidst a background of extensive ischemic changes. Conclusions: Endoscopic descriptions of colonic intussusception are unusual given their rarity. Furthermore, these lesions can mimic a colonic bezoar as a result of fecal accretion and this can ultimately lead to false diagnostic and therapeutic decisions. In such instances, clarification with a CT scan before management decision can potentially avert unnecessary endoscopic intervention and complications.