Abnormal findings on computed tomography and their relationship and significance to abnormal endoscopic investigation: A retrospective study

Background and Aim: Computed tomography (CT) imaging studies are now commonplace in primary care settings to rule out abnormalities in symptomatic patients With the advent of high-definition imaging, there has been an increase in the diagnosis of abnormalities thought to be found on CT, whether as an incidental finding or a potential cause of symptoms Many of these patients are then recommended to follow up with a gastroenterologist for consideration of endoscopic evaluation to elucidate the validity of these changes During the coronavirus disease 2019 (COVID-19) pandemic, endoscopy to evaluate imaging findings was recognized as needing case-by-case assessment of the urgency required, and gastroenterologists were advised by the Gastroenterological Society of Australia that it was reasonable to pursue endoscopic investigations if thought to be worthwhile in the context of clinical history Previous studies to evaluate the correlation between bowel wall thickening (BWT) seen on CT and endoscopy showed about 60% of patients would have findings at the site of BWT 1,2 We sought to determine the number of patients who would have significant findings on endoscopy accounting for CT imaging abnormalities in an Australian cohort Our aim was to conduct a retrospective analysis of all individuals who had positive CT findings and assess for the correlation between these positive findings and findings on endoscopy Methods: We retrospectively analyzed details of patients who underwent endoscopic procedures (including endoscopic ultrasound [EUS], endoscopic retrograde cholangiopancreatography [ERCP], flexible sigmoidoscopy, gastroscopy, or colonoscopy) secondary to abnormal CT imaging studies at two regional hospitals (Gosford and Wyong Hospitals) in the Central Coast Local Health District of New South Wales between January 2013 and April 2020 Data on patient demographics, endoscopic modality, findings on endoscopy, and histopathological diagnosis (if biopsy or polypectomy was conducted) were compiled The primary endpoint was correlation between findings on endoscopy and findings on CT imaging Results: Of the 369 patients included in this study, 183 were male and 186 were female The predominant endoscopic modality for investigation was colonoscopy (196, 53 1%), followed by gastroscopy (86, 23 3%), EUS (64, 17 3%), flexible sigmoidoscopy (19, 5 1%), and ERCP (1, 0 2%) Three patients underwent repeat endoscopy with a different modality (two gastroscopy-colonoscopy and one colonoscopy-EUS) Malignancy was found in 80 patients (21 7%), with the majority (65, 81 3%) found to be adenocarcinoma Five patients had metastatic disease from other sites of the body (four from dermatological malignancy and one with lung malignancy), five had high-grade neuroendocrine small cell carcinoma, three had B-cell lymphoma, one had a gastrointestinal stromal tumor, one had a primary squamous cell carcinoma, and five had abnormalities that remained undefined on formal histology Adenomatous polyps were found in 25 patients (6 8%), identified as tubular adenomas (11, 44%), tubulovillous adenomas (11, 44%), and sessile serrated adenomas (3, 12%) on formal histology Three patients (12%) were found to have high-grade dysplasia on formal polyp histology Diverticulosis was foundto account for abnormal imaging findings in 13 patients (4 3%), while inflammation was found in eight patients (2 2%) In total, 179 patients (48 5%) were found to have no significant findings on endoscopy, while 190 patients (51 5%) were found to have endoscopic findings that were deemed to account for the abnormal imaging studies Conclusion: The correlation between abnormal CT findings and findings in endoscopy was 51 5% This falls within a similar range as previous studies and suggests there is a high likelihood of finding abnormalities during endoscopic investigation for patients with abnormal CT findings 1,2 This study supports the recommendation for urgent endoscopy in these patients, given 19 2% of patients were found to have malignant disease that accounted for th ir abnormal CT imaging findings