Research Report
Copyright ©2014 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Apr 21, 2014; 20(15): 4377-4381
Published online Apr 21, 2014. doi: 10.3748/wjg.v20.i15.4377
Unexpected FDG-PET uptake in the gastrointestinal tract: Endoscopic and histopathological correlations
Eran Goldin, Mahmud Mahamid, Benjamin Koslowsky, Shimon Shteingart, Yael Dubner, Gadi Lalazar, Dov Wengrower
Eran Goldin, Mahmud Mahamid, Benjamin Koslowsky, Shimon Shteingart, Dov Wengrower, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, Jerusaleml 91031, Israel
Yael Dubner, Gadi Lalazar, Department of Gastroenterology, Hadassah University Hospital, Jerusaleml 91031, Israel
Author contributions: Goldin E and Mahamid M contributed equally to this article; Goldin E, Wengrower D and Mahamid M developed the concept and design of the study; Dubner Y and Lalazar G performed the acquisition of the data; Shteingart S contributed to the statistical analysis of the data, and final manuscript revisions; Koslowsky B contributed to the statistical analysis of the data and performed major article revisions including the final approval of the manuscript.
Correspondence to: Benjamin Koslowsky, MD, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, 12 Bayit street, Jerusaleml 91031, Israel. binyaminkos@szmc.org.il
Telephone: +972-2-6666064 Fax: +972-2-6666050
Received: April 8, 2013
Revised: August 6, 2013
Accepted: September 13, 2013
Published online: April 21, 2014
Abstract

AIM: To investigate the nature and significance of unexpected positron emission tomography with fluorodeoxyglucose (FDG-PET) uptake within the gastrointestinal tract (GIT).

METHODS: Patients with unexpected FDG-PET findings in the GIT were evaluated. All patients had a previous confirmed malignancy, either solid or lymphoproliferative. The radiologic reports were performed by experienced radiologists with an exclusive PET expertise. Endoscopy, i.e., esophagogastroduodenoscopy (EGD) and colonoscopy, and histopathological evaluation of all findings was performed in all patients in accordance to the FDG-PET results. The findings from each of these modalities were compared to each other. Both clinically significant and insignificant findings were assessed.

RESULTS: Seventy-two patients were endoscopically evaluated. Twenty-seven patients (37.5%) had primarily a lymphoproliferative tumor and 45 (62.5%) had solid tumors. In 50 patients (69.4%) the endoscopic examination revealed lesions in the same anatomical areas as the FDG-PET findings. Among these 50 patients, malignant and premalignant lesions i.e., adenomatous polyps were found in 16 (32%) and 9 (18%) patients, respectively. Inflammation was noted in an additional 20 patients (40%). Compared to primary solid tumors, a background of primary lymphoproliferative malignancy was more likely to reveal an additional primary malignancy (15.6% vs 33.3%, respectively, P < 0.01). EGD compared to colonoscopy, revealed altogether 11 (25.6%) new malignancies compared to 5 (17.2%), respectively, P = 0.12. No GIT clinically significant findings were overseen by the FDG-PET.

CONCLUSION: Unexpected FDG uptake in the GIT is commonly encountered and may contain significant findings. Endoscopy evaluation is justified in order to detect these additional findings.

Keywords: Positron emission tomography with fluorodeoxyglucose, Gastrointestinal tract, Malignancy, Endoscopy, Unexpected findings

Core tip: Positron emission tomography with fluorodeoxyglucose (FDG-PET) is gradually gaining acceptance as a first line radiological modality for both solid and hematological malignancies. While both technology and expertise is improving, incidental findings are more frequently encountered. The gastrointestinal tract is a common source for these unexpected findings. In this manuscript we assessed the significance of these findings and correlated them with upper and lower endoscopy findings. Surprisingly, we encountered much clinical significant information. More so, the FDG-PET was considerably sensitive to gastrointestinal findings. These results suggest that gastrointestinal incidental findings should be evaluated.