Diverticulitis and Diverticulosis of the Appendix: A Case Series

Abstract

Introduction Diverticula of the appendix is a rare entity, may be complicated by inflammation/infection, and clinically mimics acute appendicitis. The reported associated risk factors include male gender, Hirschprung's disease, cystic fibrosis and adult age, where some reports claim that they are also associated with an increased risk of appendiceal malignancy. Imaging has a place in pre-operative diagnosis, however, most of the cases were diagnosed during a pathological examination after surgery. They are associated with a higher rate of perforation (more than four times compared with classical acute appendicitis). In this review, we present a case series of five patients diagnosed with diverticulitis and one with diverticulosis of the appendix that were managed at a single centre. Our aim is to explore the common clinical, radiological, and intra-operative findings associated with this disease as well as the outcome of management. Materials and methods A total number of six cases of diverticular disease of the appendix diagnosed and managed at Basildon University hospital in the period between 2016 and 2020 were studied. The demographic details and clinical data including presenting symptoms, laboratory results, radiological characteristics, intraoperative findings and histopathological features were analysed. Results The study group included four males and two females, with an age range of 20-84 years. The most common presenting clinical symptoms were right iliac fossa abdominal pain, nausea, anorexia, and diarrhoea. Half of the cases showed a thickened appendix in the pre-operative CT scan. An inflamed or perforated appendix was seen in five cases as well as inflammation of the diverticula. Conclusion Appendiceal diverticulitis is an uncommon pathology that imitates acute appendicitis, and appendicectomy is the standard treatment. Prophylactic appendicectomy is recommended for non-inflamed diverticula - this is due to the potential risk of inflammation, perforation, and the risk of developing an appendiceal neoplasm.

Keywords: acute appendicitis; appendiceal diverticulitis; appendicectomy; computed tomography; diverticulosis; laparoscopic appendicectomy.

Figure 1. Sagittal CT Scan image of thickened appendix with extensive perifocal fat stranding.

Figure 2. Axial image of thickened appendix with extensive perifocal fat stranding. A small calcific focus (possibly a displaced appendicolith) was visualised within the lumen of the caecum.

Figure 3. Appendicular diverticulum with associated mild active chronic inflammation.

Figure 4. Part of the diverticula protrusion into the fibromuscular wall.

Figure 5. An area with severe active chronic inflammation with associated serositis.

Figure 6. Thickened and oedematous, non-compressible blind-ended bowel loop in the right iliac fossa.

Figure 7. Diverticulum with associated fibrosis of wall and mild to moderate active chronic inflammation (x2).

Figure 8. CT Scan coronal view showing thickened appendix associated with peri-appendiceal inflammatory changes within the RIF, consistent with acute appendicitis.

RIF: right iliac fossa

Figure 9. Deeply sited diverticula with associated mild acute inflammation.

Figure 10. Diverticulum extends into the surrounding fat.

Figure 11. Abdominal ultrasound scan showing a thick-walled bowel loop (measuring up to 8 mm) suggesting inflammation.

Figure 12. Large diverticulum sited deeply into an extremely thinned wall comprised mostly of fibrotic fibrofatty wall (x1.25).

Hematoxylin & Eosin x1.25

Figure 13. Large diverticulum sited deeply into an extremely thinned wall comprised mostly of fibrotic fibrofatty wall.

Hematoxylin & Eosin x2.5

Figure 14. There is an intraluminal abscess (x4).

Figure 15. Axial CT scan - a highly suspicious ruptured appendix with acute appendicitis and focal changes.

Figure 16. Transverse section of the appendix showing a linear extension of the diverticulum into the wall. There is extensive haemorrhage, necrosis, and acute inflammation.

Hematoxylin & Eosin x20

Figure 17. Longitudinal section of appendix towards the tip showing ruptured diverticular with tissue necrosis and acute inflammation.

Hematoxylin & Eosin x12.5 (1.25 objective)

Figure 18. Figure shows the severity of acute inflammation, including intramural abscess.

Hematoxylin & Eosin x40 (x4 objective)

Figure 19. Longitudinal section toward the base of the appendix showing multiple diverticular protrusions through the wall. There is associated mild diverticulitis.

Hematoxylin & Eosin x12.5 (objective 1.25)

Figure 20. Transverse section of the mid-segment of the appendix also showing diverticular disease of the appendix.

Hematoxylin & Eosin x12.5 (objective 1.25)