Colonoscopic Appearances of an Appendiceal Remnant: The Benign Masquerading as the Sinister

CASE REPORT

A 50-year-old woman presented with a 3-month history of alternating diarrhea and constipation, with no associated weight loss. Her only medical history was that of an emergency appendectomy 33 years ago. The patient's blood investigations and stool samples were unremarkable. Her family physician organized a virtual colonoscopy to investigate any underlying pathology. Imaging revealed a heterogeneous mass in the cecum along with several small nonpathological nodes along the draining vascular chain (Figure 1). She subsequently underwent an urgent colonoscopy which revealed a 5-cm pedunculated polyp (Paris 1p) at the cecal pole (Figure 2). Image-enhanced endoscopy revealed round pits and the absence of meshed capillary vessels (Kudo I) (Figure 3). Biopsies revealed fragments of large bowel mucosa with a diffuse increase in chronic inflammatory cells in the lamina propria and reactive lymphoid follicle. The radiological and endoscopic findings were in keeping with an inverted appendiceal remnant.

Figure 1.: Axial view of the computed tomography colonography demonstrating a 15-mm filling defect at the cecal pole (arrow).

Figure 2.: Colonoscopy showing polyps in the cecum.

Figure 3.: Narrowband image of the cecal polyp.

Appendiceal remnants are an unusual finding both endoscopically and radiologically and can be mistaken for pathological processes such as polyps or malignant lesions.¹ They most often occur because of intussusception or postappendectomy through the inversion-ligation method.¹ In this approach, the appendix base is initially ligated, then cut. The appendiceal stump is subsequently inverted into the lumen of the cecum, and a purse-string suture is tied to close.² This technique was commonly performed by surgeons to theoretically reduce the risk of peritoneal contamination in the setting of acute appendicitis. The inverted appendiceal stump usually necroses if the vascular supply is adequately occluded during suturing and sloughs away after several days.³ However, remnant tissue from the appendix may persist in some patients. This procedure has now been replaced by simple ligation because this has lower operating times and fewer endoscopic misdiagnoses. Despite this, appendiceal remnants protruding into the colonic lumen can occur after any surgical procedure involving the appendix.⁴ Anecdotally, routine removal of these lesions has been associated with perforation or bleeding if the appendiceal lumen or blood supply is still intact.⁴

This case highlights the importance of obtaining a thorough medical and surgical history. The case also reaffirms the importance of a comprehensive endoscopic assessment of all polyps using a combination of white light endoscopy in addition to chromoendoscopy adjuncts. Although adenomatous lesions are the most typical type of the polyp detected during a screening colonoscopy, it is essential to use validated classifications to rule out benign and other differentials that mimic more sinister pathology (Figure 4).⁵

Figure 4.: Kudo's pit pattern classification for colorectal neoplasms.

DISCLOSURE

Author contributions: H. N. Haboubi and J. H. Hassall wrote and edited the manuscript. H. L. Collins edited the manuscript. R. Ellis-Owen provided the radiological images. J. Green approved the final manuscript. H. Haboubi is the article guarantor.

Financial disclosure: None to report.

Informed consent was obtained for this case report.