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Scientific Session 08 — SS08: Gastrointestinal Imaging - General GI

Tuesday, May 7, 2019

Abstracts 1699-3046

2518. Traditional Serrated Adenomas at CT Colonography: International Multicenter Experience

Ruby J1*,  Pusceddu L2,  Park S3,  Plumb A4,  Pickhardt P1 1. University of Wisconsin School of Medicine, Madison, WI; 2. University of Torino, Candiolo, Italy; 3. University of Ulsan College of Medicine, Seoul, Republic of Korea; 4. University College London, London, England

Address correspondence to J. Ruby (

Objective: Serrated polyps include hyperplastic polyps (HPs), sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas (TSAs). HPs and SSA/Ps account for approximately 99% of all serrated lesions; TSAs are rare. However, both SSA/Ps and TSAs are now recognized as precursor lesions to carcinogenesis, representing approximately one-fourth of all sporadic colorectal cancers. Extensive research has been published describing HPs and SSA/Ps, but there is a paucity of information on TSAs owing to its rarity. We report the first series describing TSA characteristics at CT colonography (CTC).

Materials and Methods: An international multicenter retrospective review of CTC-detected TSAs diagnosed between 2008 and 2018 was conducted. Data collection was approved by the representative institutional review boards of each of the four contributing sites, representing patient populations in the United States, United Kingdom, Italy, and South Korea. Data collected included patient demographics, CTC, optical colonoscopy, and pathology information.

Results: A total of 57 proven TSAs in 48 patients (mean age, 64.3 years) were identified for the series. The majority of TSAs (67%) were located in the distal colon (descending, sigmoid, and rectum). Mean TSA size was 16 mm (range, 3 - 55 mm). Morphology of small (<10 mm) TSAs was typically simple sessile/polypoid, whereas morphology of larger (10 mm) TSAs tended to be more lobulated and irregular, either pedunculated or carpet-like. Tagging agents used included barium- and iodine-based agents (diatrizoate and iohexol); most TSAs (89%) in patients who consumed oral contrast agent demonstrated at least some lesional surface tagging of oral contrast agent.

Conclusion: We report the first multicenter experience of TSAs at CTC. Unlike sessile serrated lesions, TSAs are more often left sided and tend to be more lobulated and irregular. However, like SSA/Ps, most TSAs demonstrate oral contrast coating. Detection of these rare lesions at CTC is important, given their malignant potential.