DOI: 10.1148/rg.266065019
RadioGraphics 2006;26:1869-1872
© RSNA, 2006
Best Cases from the AFIP
Giant Colonic Diverticulum1
Stephen Thomas, MD,
Robert L. Peel, MD,
Leonard E. Evans, MD and
Kelly A. Haarer, MD
1 From the Departments of Radiology (S.T., K.A.H.), Pathology (R.L.P.), and Surgery (L.E.E.), University of Pittsburgh Medical Center, 200 Lothrop St, Pittsburgh, PA 15213-2582. Received March 3, 2006; revision requested April 17 and received June 14; accepted June 15. All authors have no financial relationships to disclose.
Address correspondence to K.A.H. (e-mail: haarerka{at}upmc.edu).
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History
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A 70-year-old retired man with a history of colonic diverticulosis presented with painless rectal bleeding. Radionuclide imaging and abdominal computed tomography (CT) were performed to detect and localize the source of the bleeding. An enema study with a water-soluble contrast agent was also performed.
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Imaging Findings
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Radionuclide images obtained with technetium 99m demonstrated a rim of moderately increased radiotracer with a central area of photopenia, findings that indicate hyperemia without active bleeding (Fig 1).
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Figure 1. Tc-99m radionuclide images show a rim of increased radiotracer uptake (arrowheads) with central photopenia adjacent to the aortic bifurcation. These findings represent hyperemia.
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Unenhanced CT (with 5.0-mm-thick sections) of the abdomen and pelvis was performed. The scout view demonstrated a large, round, smooth-walled, gas-filled mass in the pelvis (Fig 2). An axial scan through the area showed a slightly thick-walled, 9 x 9-cm cystic mass with an air-fluid level that appeared to arise from the sigmoid colon (Fig 3). Numerous diverticula were seen in the sigmoid colon, as well as inflammatory changes in the surrounding mesentery. The urinary bladder appeared normal. In an enema study performed with water-soluble contrast agent, the mass filled with contrast material, demonstrating communication with the sigmoid colon (Fig 4). Multiple diverticula in the sigmoid colon were also seen. From these imaging features, a giant sigmoid diverticulum was suspected.
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Figure 3. Axial unenhanced CT scan of the abdomen shows a 9 x 9-cm cystic mass with an air-fluid level (arrowhead). The mass has a thickened wall and is in continuity with the sigmoid colon. Inflammation of the surrounding mesentery is seen.
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Figure 4. Image from a contrast enema study demonstrates a mass (*) with a smooth wall that fills with contrast material from the sigmoid colon. The sigmoid colon has numerous diverticula (arrowheads).
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Pathologic Evaluation
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The patient underwent definitive surgical treatment, with resection of the involved segment of sigmoid colon and primary anastomosis. Gross pathologic evaluation of the resected segment showed a 7.5-cm mass arising from the mesenteric side of the sigmoid colon (Fig 5a). The mass had an inflamed red-brown surface lining, and the outer wall measured 1 cm in thickness (Fig 5b). The resected colonic segment also had numerous diverticula.
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Figure 5a. (a) Photograph of the resected colonic segment shows a large mass arising from the segment. Scale is in centimeters. (b) Photograph of the sectioned surgical specimen shows that the mass is extraluminal, with a connection to the colon (arrowhead). The diverticulum contained fecal material.
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Figure 5b. (a) Photograph of the resected colonic segment shows a large mass arising from the segment. Scale is in centimeters. (b) Photograph of the sectioned surgical specimen shows that the mass is extraluminal, with a connection to the colon (arrowhead). The diverticulum contained fecal material.
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Microscopic examination of the wall revealed an incomplete colonic mucosal lining interspersed with granulation tissue and no colonic muscularis propria layer (Fig 6), findings indicative of a pseudodiverticulum. The pathologic diagnosis was a giant inflammatory pseudodiverticulum of the sigmoid colon without coexisting malignancy.
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Discussion
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Despite the high prevalence of diverticular disease in the Western world, giant colonic diverticula are rare, with only 135 cases described (1). The majority of patients present after the 6th decade of life (2). The most frequent presenting symptoms of giant colonic diverticula are abdominal pain, nausea, vomiting, fever, constipation, diarrhea, and melena. The two most common complications of giant colonic diverticulum are perforation and abscess formation (3).
The majority (93%) of giant colonic diverticula arise from the sigmoid colon, at the side of penetrating blood vessels in the mesenteric border, and they are associated with diverticular disease (4). Giant colonic diverticula can be separated based on histologic characteristics into three types (5). The majority (66%) of giant colonic diverticula are of the inflammatory type, 22% are pseudodiverticula, and 12% are true diverticula (1).
In a giant pseudodiverticulum, the true colonic muscularis propria ends abruptly at the neck of the pseudodiverticulum. However, remnants of the muscularis mucosae may be found in the diverticulum wall. The colonic mucosal lining is often incomplete and is interspersed with chronic granulation tissue (1).
In giant inflammatory diverticulum, the diverticulum wall is made up of dense fibrous tissue, chronic inflammatory cells, and foreign body giant cells (7). It has been suggested that this composition may result from degeneration of the mucosal lining of a pseudodiverticulum (8). According to an alternate theory, giant colonic diverticulum may develop as a result of a contained perforation that grows either because of a ball-valve mechanism or from gas-forming organisms (9).
In true giant colonic diverticulum, its wall contains all colonic layers and it likely represents a communicating bowel duplication cyst (6). In rare cases, the wall may contain other substances or disease, including amyloid (10), lymphoma of mucosa-associated lymphoid tissue (MALT) (11), and urothelium (12).
Barium or water-soluble contrast enema examinations and CT are commonly used to diagnose giant colonic diverticula. The differential diagnosis for giant colonic diverticulum includes volvulus, bowel duplication, Meckel and duodenal diverticula, infected pancreatic pseudocyst, emphysematous cholecystitis, emphysematous cystitis, vesicoenteric fistula, and abscess (3).
In a contrast enema study, the diverticulum is opacified in 60% of the cases. The wall of the giant colonic diverticulum should be smooth and regular. If it has irregular or lobulated margins, coexisting neoplasm should be excluded (4). At CT, the diverticulum appears as a cavity filled with gas, fluid, or stool, with a thin regular wall and no contrast enhancement except in the presence of inflammation. The wall may contain calcifications from chronic inflammation. A thick wall is associated with acute inflammation, as with diverticulitis (13).
The definitive treatment for giant diverticula is surgery. Resection of the involved segment with primary anastomosis is the treatment of choice. However, in complicated cases such as those with coexisting carcinoma, a two-stage bowel resection with colostomy (Hartmann procedure) is performed. In cases with perforation with localized abscess, percutaneous drainage is recommended (3).
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Footnotes
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Editor’s Note.—Everyone who has taken the course in radiologic pathology at the Armed Forces Institute of Pathology (AFIP) remembers bringing beautifully illustrated cases for accession to the Institute. In recent years, the staff of the Department of Radiologic Pathology has judged the "best cases" by organ system, and recognition is given to the winners on the last day of the class. With each issue of RadioGraphics, one or more of these cases are published, written by the winning resident. Radiologic-pathologic correlation is emphasized, and the causes of the imaging signs of various diseases are illustrated.
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References
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- Steenvoorde P, Vogelaar FJ, Oskam J, Tollenaar RA. Giant colonic diverticula: review of diagnostic and therapeutic options. Dig Surg 2004;21(1): 1–6.[CrossRef][Medline]
- de Oliveira NC, Welch JP. Giant diverticula of the colon: a clinical assessment. Am J Gastroenterol 1997;92:1092–1096.[Medline]
- Custer TJ, Blevins DV, Vara TM. Giant colonic diverticulum: a rare manifestation of a common disease. J Gastrointest Surg 1999;3(5):543–548.[CrossRef][Medline]
- Roger T, Rommens J, Bailly JM, Vollont GH, Belva P, Delcour C. Giant colonic diverticulum: presentation of one case and review of the literature. Abdom Imaging 1996;21(6):530–533.[CrossRef][Medline]
- McNutt R, Schmitt D, Schulte W. Giant colonic diverticula—three distinct entities: report of a case. Dis Colon Rectum 1988;31(8):624–628.[CrossRef][Medline]
- Choong CK, Frizelle FA. Giant colonic diverticulum: report of four cases and review of the literature. Dis Colon Rectum 1998;41(9):1178–1185.[CrossRef][Medline]
- Mehta DC, Baum JA, Dave PB, Gumaste VV. Giant sigmoid diverticulum: report of two cases and endoscopic recognition. Am J Gastroenterol 1996; 91:1269–1271.[Medline]
- Casas DJ, Tenesa M, Alastrue A, Hidalgo F, Barranco LC, Olazabal A. Case report: uncommon radiological and pathological features of giant colonic diverticula. Clin Radiol 1991;44(2):125–127.[CrossRef][Medline]
- Boijsen E. Riesendivertikel im sigmoid. Fortschr Geb Rontgenstr Nuklearmed 1956;84:760–761.[Medline]
- Diaz Candamio MJ, Pombo F, Yebra MT. Amyloidosis presenting as a perforated giant colonic diverticulum. Eur Radiol 1999;9(4):715–718.[CrossRef][Medline]
- Arima N, Tanimoto A, Hamada T, Sasaguri Y, Sasaki E, Shimokobe T. MALT lymphoma arising in giant diverticulum of ascending colon. Am J Gastroenterol 2000;95(12):3673–3674.[CrossRef][Medline]
- Rosen NG, Gibbs DL, Soffer SZ, Valderrama E, Lee TK. Uroepithelium in a colonic diverticulum. J Pediatr Surg 2000;35(9):1375–1376.[CrossRef][Medline]
- Fields SI, Haskell L, Libson E. CT appearance of giant colonic diverticulum. Gastrointest Radiol 1987;12(1):71–72.[CrossRef][Medline]
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History
Imaging Findings
