A giant colonic diverticulum is a rare form of presentation of colonic diverticulosis and is characterised by a large diverticular mass, usually filled with stool and gas, that communicates with the colonic lumen.
The most common presentation is abdominal pain. Other presenting symptoms include constipation, abdominal masses, vomiting, diarrhoea and rectal bleeding 5.
The majority (>90%) arise from the sigmoid colon 1,3, but they can occur in any part of the colon.
They are thought to arise either from:
- pseudodiverticula of the sigmoid colon in which the mucosa herniates through the muscular wall and becomes progressively enlarged by colonic gas via a ball-valve type mechanism 4
- gas-forming organisms present in an already formed pseudodiverticulum produce gas, which progressively distends the diverticulum 4
Abdominal x-rays may show large gas-filled cysts with a gas-fluid level 5.
CT is the best imaging modality for diagnosis given that colonoscopies are rarely carried out due to the risk of perforation 2. CT shows the diverticulum as a gas, fluid or faeces-filled cavity, sometimes with calcification in the case of chronic inflammation. There is usually no contrast enhancement unless there is active inflammation 2.
Treatment and prognosis
The definitive treatment for a giant diverticulum is surgery 2.
- 1. Custer TJ, Blevins DV, Vara TM. Giant colonic diverticulum: a rare manifestation of a common disease. J. Gastrointest. Surg. 2000;3 (5): 543-8. Pubmed citation
- 2. Thomas S, Peel RL, Evans LE et-al. Best cases from the AFIP: Giant colonic diverticulum. Radiographics. 2006;26 (6): 1869-72. doi:10.1148/rg.266065019 - Pubmed citation
- 3. McQuade KL, Foreman ML. Giant colonic diverticulum. Proc (Bayl Univ Med Cent). 2011;21 (1): 25-6. Free text at pubmed - Pubmed citation
- 4. Kempczinski RF, Ferrucci JT. Giant sigmoid diverticula: a review. (1974) Annals of surgery. 180 (6): 864-7. Pubmed
- 5. Nigri G, Petrucciani N, Giannini G, et al. Giant colonic diverticulum: Clinical presentation, diagnosis and treatment: Systematic review of 166 cases. World Journal of Gastroenterology : WJG. 2015;21(1):360-368. doi:10.3748/wjg.v21.i1.360. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284356/