Case Report
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jul 6, 2022; 10(19): 6710-6715
Published online Jul 6, 2022. doi: 10.12998/wjcc.v10.i19.6710
Delayed-release oral mesalamine tablet mimicking a small jejunal gastrointestinal stromal tumor: A case report
Fabio Frosio, Emanuele Rausa, Paolo Marra, Marie-Christine Boutron-Ruault, Alessandro Lucianetti
Fabio Frosio, Emanuele Rausa, Alessandro Lucianetti, Department of General Surgery, ASST Papa Giovanni XXIII Hospital, Bergamo 24127, Italy
Paolo Marra, Department of Radiology, ASST Papa Giovanni XXIII Hospital, Bergamo 24127, Italy
Marie-Christine Boutron-Ruault, Paris-Saclay University, UVSQ, Inserm, Gustave Roussy, Exposome and Heredity Team, Centre for Epidemiology and Population Health (CESP U1018), Villejuif 94800, France
Author contributions: Frosio F collected the data and wrote the paper; Rausa E reviewed the literature; Marra P reviewed the CT images; Boutron-Ruault MC critically revised the manuscript; Lucianetti A gave the input in realizing this case report and critically revised it; and All authors gave their approval to the submitted version.
Informed consent statement: Informed written consent was obtained from the patient for publishing this case report of this report and any accompanying images.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Fabio Frosio, MD, Surgeon, Department of General Surgery, ASST Papa Giovanni XXIII Hospital, Piazza OMS 1, Bergamo 24127, Italy.
Received: January 24, 2022
Peer-review started: January 24, 2022
First decision: March 12, 2022
Revised: April 13, 2022
Accepted: May 17, 2022
Article in press: May 17, 2022
Published online: July 6, 2022

Enteric-coated medications are supposed to pass intact through the gastric environment and to release the drug content into the small intestine or the colon. Before dissolution of the enteric coating, they may appear hyperdense on computed tomography (CT). Unfortunately, few reports have been published on this topic so far. In this case report, the hyperdense appearance on contrast-enhanced CT of an enteric-coated mesalamine tablet was initially misinterpreted as a jejunal gastrointestinal stromal tumor (GIST).


An asymptomatic 81-year-old male patient, who had undergone laparoscopic right nephrectomy four years earlier for stage 1 renal carcinoma, was diagnosed with a jejunal GIST at the 4-year follow-up thoraco-abdominal CT scan. He was referred to our hub hospital for gastroenterological evaluation, and subsequently underwent 18-fluorodeoxyglucose positron emission tomography, abdominal magnetic resonance imaging, and video capsule endoscopy. None of these examinations detected any lesion of the small intestine. After reviewing all the CT images in a multidisciplinary setting, the panel estimated that the hyperdense jejunal image was consistent with a tablet rather than a GIST. The tablet was an 800 mg delayed-release enteric-coated oral mesalamine tablet (Asacol®), which had been prescribed for non-specific colitis, while not informing the hospital physicians.


Delayed-release oral mesalamine (Asacol®), like other enteric-coated medications, can appear as a hyperdense image on a CT scan, mimicking a small intestinal GIST. Therefore, a detailed knowledge of the patients’ medications and a multidisciplinary review of the images are essential.

Keywords: Mesalamine, Enteric-coating, Asacol, Tablet, Gastrointestinal stromal tumor, Case report

Core Tip: Enteric-coated tablets may appear as hyperdense images on computed tomography (CT) scan, and lead to misdiagnosis, for example of small intestinal gastrointestinal stromal tumors which usually show homogeneous enhancement on contrast-enhanced CT phases. Therefore, when observing small hyperdense lesions in the gastrointestinal tract on CT scan, physicians should be aware of possible radiopaque medications. A perfect knowledge of the patients’ medical treatment (even occasional) and a multidisciplinary review of all the images are essential to avoid misdiagnosis and unnecessary investigations.