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CC BY 4.0 · Ibnosina Journal of Medicine and Biomedical Sciences
DOI: 10.1055/s-0045-1815705
Original Article

Computed Tomography Imaging Evaluation and Outcome of Isolated Sigmoid Colon Thickening

Authors

  • Khawaja Bilal Waheed

    1   Department of Radiology, King Fahad Military Medical Complex, Dhahran, Saudi Arabia

  • Alexander Woodman 

    2   School of Health Sciences, University of Salford, Manchester, United Kingdom

  • Lamiaa H. Al-Jamea

    3   Department of Academic Affairs and Training, King Fahad Military Medical Complex, Dhahran, Saudi Arabia

  • Arulanantham Z. Jebakumar

    4   Postgraduate Studies and Scientific Research Department, Prince Sultan Military College of Health Sciences, Dammam, Saudi Arabia

  • Meshari Abdullah Hamad Al-Faris

    1   Department of Radiology, King Fahad Military Medical Complex, Dhahran, Saudi Arabia

Funding and Sponsorship None.
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Abstract

Background

This research aimed to evaluate computed tomography (CT) imaging findings in patients presenting with isolated sigmoid colon wall thickening based on their CT studies and to correlate these with biopsy results.

Materials and Methods

This retrospective observational study evaluated CT imaging data of all consecutive adult patients who presented with acute lower abdominal pains in emergency departments and were found to have isolated sigmoid colonic thickening on routine portal venous phase CT studies, between January 2020 and January 2022. CT findings associated with the length of the affected sigmoid segment, mucosal pattern (symmetric or asymmetric), presence of diverticula, lymph nodes, and other additional features were documented. Age, gender, and CT findings were compared with outcomes, and associations were determined by the Chi-square test.

Results

Of the 30 patients (aged between 20 and 75 years), the majority were males (n = 21) and older than 40 years (n = 22). In n = 16 cases, the clinical picture was acute (without the presence of diverticula), and in n = 14 cases, it was chronic (with the presence of diverticula). Both findings were statistically significant with p = 0.01 for each. Acute presentation, younger patients, and the presence of diverticula on CT scans were associated with benign biopsies. Length of mucosal thickening of the affected segment (i.e., less than 10 cm) and the presence of diverticula exhibited the most effective predictive association for the benign outcome.

Conclusion

Younger patients who present acutely and show diverticula on CT imaging may have benign causes of sigmoid thickening, which may ultimately require endoscopic evaluation to exclude malignancy, particularly in cases of complicated diverticulitis or when CT finds are challenging.


Keywords

computed tomography - sigmoid colon thickening - colonic malignancies - benign and malignant - diverticulitis

Introduction

Lower abdominal pain is a common presentation in patients visiting the emergency department.[1] Although a provisional diagnosis can be made based on clinical presentation and physical examination, imaging plays a pivotal in establishing the diagnosis and directing clinical management.[2] Acute diverticulitis is among the common causes of left iliac fossa pain.[3] Clinical history may vary from a few months of insidious pain to rapidly evolving or severe pain, especially during straining at defecation. Symptoms may affect middle-aged to old-aged persons and depend upon disease severity or its complications. The sigmoid colon is the commonly affected segment. Colonic malignancy can also affect the same bowel segment. The presentation may be acute or with prolonged duration, mimicking acute or chronic diverticulitis, respectively thereby delaying diagnosis.[1] [2] [3] [4]

Imaging findings can also overlap with those of benign inflammatory or infectious colitis and colonic malignancy.[5] Secondary diverticula can be seen in malignancies as a result of obstructive motility. Therefore, meticulous evaluation of the clinical presentation and imaging findings is vital for reaching a correct diagnosis. Subsequent endoscopy and histopathologic correlation may be necessary to establish a diagnosis for the early management of sinister pathology and to avoid overlooking malignancy.[6] Based on this brief evidence, this research aimed to evaluate CT imaging findings in patients with isolated sigmoid colonic thickening found on their computed tomography (CT) studies and to correlate these findings with biopsy results.


Materials and Methods

Design and Setting

A retrospective observational study was conducted in Department of Radiology at King Fahad Military Medical Complex hospital in Dhahran, between January 2020 and January 2022. The study evaluated data from all consecutive adult patients who presented to the emergency department with acute left lower abdominal pain and were found to have isolated sigmoid colonic wall thickening on routine portal venous-phase intravenous contrast-enhanced CT studies.


Procedures

The study was approved by King Fahad Military Medical Complex Ethics Committee. The need for informed written consent was waived considering its retrospective nature and the non-disclosure of patient information. The research was conducted in accordance with the Helsinki Declaration.


Data Collection

Patients with previous bowel-related surgeries, known inflammatory bowel disease, or a history of sigmoid malignancy (diagnosed or operated) were excluded. Data from patients who did not go through endoscopies or were lost to follow-ups were not considered in the study. CT findings associated with the length of sigmoid segment affected (≤10 cm or ≥10 cm), mucosal pattern (symmetric and ≤10-mm thickness or asymmetric and ≥10-mm thickness), presence of diverticula, lymph nodes, and other features (pericolic abscess or fistula formation, extra-luminal air foci or perforation, local invasion) were documented. Two experienced radiologists performed consensus reporting, and minor differences were resolved by mutual agreement with another senior staff member. Final diagnoses were confirmed by colonoscopy biopsy results.


Data Analysis

Data were collected and analyzed using IBM SPSS Statistics for Windows, version 22 (IBM Corp., Armonk, New York, United States). Demographic information and CT findings were compared with outcomes, and associations were determined by the Chi-square test and Fisher's Exact test.



Results

Of the 30 patients (aged between 20 and 75 years), the majority were males (n = 21) and above 40 years of age (n = 22) ([Table 1]). Endoscopic data showed that, of n = 30 cases, n = 18 were benign and n = 12 were cancerous. In n = 16 cases, the clinical picture was acute (without diverticula), and in n = 14 cases, it was chronic (with diverticula). Both findings were statistically significant with p = 0.01 for each. Further analysis showed that people over 40 years of age were more likely to have both malignant and benign tumors, although this was not statistically significant (p = 0.06).

Table 1

Demographic, clinical, imaging, and endoscopic characteristics of study population

Study variables

Endoscopic result

Total

p-Value

Benign n (%)

Malignant n (%)

Age group

Less than 40 y

7 (87.5)

1 (12.5)

8

0.06

More than 40 y

11 (50)

11 (50)

22

Gender

Male

13 (61.9)

8 (38.1)

21

0.75

Female

5 (55.6)

4 (44.4)

9

Clinical presentation

Acute

13 (81.3)

3 (18.8)

16

0.01[a]

Chronic

5 (35.7)

9 (64.3)

14

Length of the affected segment

Less than 10 cm

8 (61.5)

5 (38.5)

13

0.88

More than 10 cm

10 (58.8)

7 (41.2)

17

Mucosal thickening

Asymmetrical

3 (37.5)

5 (62.5)

8

0.13

Symmetrical

15 (68.2)

7 (31.8)

22

Presence of diverticula

Present

12 (85.7)

2 (14.3)

14

0.01[a]

Not present

6 (37.5)

10 (62.5)

16

Lymph node

Present

9 (52.9)

8 (47.1)

17

0.37

Not present

9 (69.2)

4 (30.8)

13

Additional findings

Present

12 (63.2)

7 (36.8)

19

0.64

Not present

6 (54.5)

5 (45.5)

11

Note: Association tables for study parameters as determined by Chi-square and Fisher's Exact test.


a Significant at 95%.


Of the 30 patients, n = 12 patients had colonic malignancies while 18 had benign findings ([Fig. 1]). Acute presentation, younger patients, and those showing presence of diverticula on CT scans were seen as associated with benign biopsies. Benign findings included inflammatory colitis (n = 13), infectious causes (n = 3), and segmental colitis associated with diverticulosis in two patients. Length of mucosal thickening of affected segment (i.e., less than 10 cm) and the presence of diverticula were the most predictive factors for a benign outcome ([Table 2], [Fig. 2]).

Zoom
Fig. 1 Selected axial CT images of two patients with sigmoid thickening with (A) benign and (B) malignant results.
Table 2

Binary logistic regression model for all the related factors against the dependent variable (endoscopy outcome)

Independent characters

B

SE

Wald

df

p-Value

Odds ratio

95% C.I. for Odds ratio

Lower

Upper

Gender (male)

0.077

1.265

0.004

1

0.951

1.080

0.091

12.883

Clinical presentation (acute)

2.723

1.475

3.407

1

0.065

15.226

0.845

274.410

Length of the affected segment (less than 10 cm)

3.900

1.884

4.286

1

0.038[a]

49.395

1.231

1,982.265

Mucosal thickening (Symmetrical)

3.452

1.821

3.594

1

0.058

31.558

0.890

1,119.238

Degree of mucosal thickening (More than 1 cm)

−22.301

40,192.970

0.000

1

1.000

0.000

0.000

.

Presence of diverticula (present)

2.689

1.366

3.873

1

0.049

14.714

1.011

214.121

Lymph node (present)

0.394

1.201

0.107

1

0.743

1.482

0.141

15.618

Additional findings (present)

–.041

1.291

0.001

1

0.974

0.959

0.076

12.049

Constant

−6.725

2.819

5.689

1

0.017

0.001

a Significant at 95%.


Zoom
Fig. 2 Bar chart demonstrating presence of diverticula in most of the benign conditions.

Discussion

Sigmoid thickening can be a non-specific finding, with a wide range of possibilities, from peristaltic contraction to colitis or even malignancy.[3] [6] Imaging evaluation of isolated sigmoid colon thickening can be challenging, particularly in older patients or in susceptible young populations with a family history of colon cancer or polyposis syndromes. Advanced imaging techniques, such as positron emission tomography (PET), may sometimes be required. However, the availability of these techniques is limited in many hospitals. Furthermore, due to the high rate of false-positive results caused by increased metabolic activity during inflammation, which can mimic drug accumulation by cancer cells, their use in the emergency setting is limited for differentiating acute colon inflammation from malignancies.[6] [7]

The findings of this study emphasize the importance of clinical presentation and the role of routine CT in benign versus malignant causes of sigmoid thickening that can make a difference in difficult or challenging cases. The findings showed that the presence of diverticula in young patients (below 40 years) who presented acutely was associated with benign histopathology. The incidence of primary neoplasms arising in bladder diverticula ranges from 0.8 to 14.3%, and their association with adjacent inflammatory changes may reliably indicate thickening related to diverticulitis.[8] The presentation can be acute or involve chronic recurrent symptoms related to lower abdominal pain and/ or obstruction. Associated imaging findings, such as intraluminal high density/hemorrhage (if plain study acquired), localized pericolic fluid collection/ abscess, or extraluminal air foci/perforation can assist in diagnosis. The Traditional Hinchey classification may help grade disease severity and in segregating patients for medical management or those requiring surgery. Fisher found bowel wall thickening to be a non-specific finding, while the presence of finger-like projections was associated with benign inflammatory changes.[7] The presence of a larger inflamed diverticulum showing a conical or pointed appearance and associated pericolic findings is mostly associated with acute diverticulitis. However, malignancy within a large diverticulum has also been documented as a rare entity.[9]

Cai et al noted a significantly higher percentage (96%) of associated abnormalities in patients with mucosal thickening of the sigmoid on CT.[10] Therefore, careful evaluation of the entire scan can identify other abnormalities, such as hepatic or bony metastases, which may indicate more serious or cancerous causes of sigmoid thickening. Lips et al found that more than half of older patients (115 out of 212 patients) presenting with mass-like thickening of the sigmoid on CT colonography had sigmoid malignancy.[11] The authors highlighted a similar finding: the absence of diverticula, as well as the shoulder phenomenon (raised mucosal margin), in these patients had a high negative predictive value for malignancy. Such findings can be more accurately studied and picked up in specialized CT colonography studies rather than on unprepared bowel because of adequate bowel distension and negative intraluminal contrast (water). Peristalsis and collapse of bowel segment further limit thorough evaluation.

CT imaging represents the standard to classify the severity of diverticulitis. Non-operative management is primarily based on antibiotics and supportive measures, but antibiotics may be omitted in mild cases. Interval colonoscopy remains advisable after an acute attack, particularly following a complicated form. Acute surgery is needed for the most severe or refractory cases, whereas elective resections are individualized and should be considered for chronic, smoldering, or recurrent forms and respective complications (stricture, fistula, etc.) and patients with factors highly predictive of recurrent attacks.

Many other specialized CT parameters can be used to identify benign and malignant causes. Goh et al compared CT perfusion measurements with morphologic criteria in 60 prospective patients for differentiating diverticulitis from carcinoma.[12] They measured mean blood volume, blood flow, transit time, and permeability and found significant differences between patients with cancer and those with diverticulitis (p < 0.0001); patients with cancer had the highest blood volume, blood flow, and permeability and the shortest transit time. The incorporation of such techniques in imaging algorithms for the evaluation of such cases should be emphasized.

The single-center, retrospective design and small sample size are some of the evident limitations of this study. In addition, routine contrast-enhanced portovenous phase CT studies were used in our study rather than CT colonographies (as bowel preparations were difficult for emergency patients and also required patient's fitness, consent or preferences), which may limit the true extent to which CT can differentiate mucosal details and assess the full extent of abnormality. Despite the reasonable length of the study period, the sample size remains relatively small. Large multicenter studies are needed in future to validate findings or identify more effective methods for diagnosing benign diseases using imaging, thereby reducing the need for biopsy. Less stringent exclusion criteria could also be considered in such studies. Additionally, future studies may consider using advanced techniques such as PET-CT or CT colonoscopy, which may provide more detailed information.


Conclusion

Clinical follow up and/or imaging are recommended after an attack of acute diverticulitis particularly if non-resolving or recurrent while colonoscopy is a crucial diagnostic tool for biopsy of an asymmetric mucosal thickening with pericolic lymph nodes to exclude underlying malignancy. Colonoscopy allows the physician to directly visualize the affected area, determine the cause of the thickening, and obtain a biopsy for a definitive diagnosis. This study found that younger patients who present acutely and have diverticula detected on CT may have benign causes of sigmoid colon thickening, which may ultimately require endoscopic evaluation to exclude malignancy, particularly in complicated diverticulitis or with challenging CT findings.



Conflict of Interest

None declared.

Authors' Contributions

K.B.W. conceptualized the draft and prepared its methodology. A.W. and L.H.A. validated the draft. K.B.W., A.Z.J., and M.A.H.A. did the formal analysis. K.B.W. wrote and prepared the original draft. A.W. and L.H.A. wrote, reviewed, and edited the manuscript. K.B.W., A.W., L.H.A., A.Z.J., and M.A.H.A. visualized the manuscript. All authors read and agreed to the published version of the manuscript.


Compliance with Ethical Principles

The study was approved by King Fahad Military Medical Complex Ethics Committee. The need for informed written consent was waived considering its retrospective nature and non-disclosure of patient information. The research was conducted in accordance with the Helsinki Declaration.



Address for correspondence

Alexander Woodman, PhD
School of Health Sciences, University of Salford, Manchester M5 4WT
United Kingdom   

Publication History

Article published online:
16 January 2026

© 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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Zoom
Fig. 1 Selected axial CT images of two patients with sigmoid thickening with (A) benign and (B) malignant results.
Zoom
Fig. 2 Bar chart demonstrating presence of diverticula in most of the benign conditions.