Unexpected FDG-PET uptake in the gastrointestinal tract: endoscopic and histopathological correlations.
OBJECTIVE
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.


CONCLUSIONS
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.
Goldin Eran, Mahamid Mahmud, Koslowsky Benjamin, Shteingart Shimon, Wengrower Dov, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, Jerusaleml 91031, Israel.
Eran
E
Goldin
Goldin Eran, Mahamid Mahmud, Koslowsky Benjamin, Shteingart Shimon, Wengrower Dov, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, Jerusaleml 91031, Israel.
Mahmud
M
Mahamid
Goldin Eran, Mahamid Mahmud, Koslowsky Benjamin, Shteingart Shimon, Wengrower Dov, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, Jerusaleml 91031, Israel.
Benjamin
B
Koslowsky
Goldin Eran, Mahamid Mahmud, Koslowsky Benjamin, Shteingart Shimon, Wengrower Dov, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, Jerusaleml 91031, Israel.
Shimon
S
Shteingart
Goldin Eran, Mahamid Mahmud, Koslowsky Benjamin, Shteingart Shimon, Wengrower Dov, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, Jerusaleml 91031, Israel.
Yael
Y
Dubner
Goldin Eran, Mahamid Mahmud, Koslowsky Benjamin, Shteingart Shimon, Wengrower Dov, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, Jerusaleml 91031, Israel.
Gadi
G
Lalazar
Goldin Eran, Mahamid Mahmud, Koslowsky Benjamin, Shteingart Shimon, Wengrower Dov, Digestive Diseases Institute, Shaare Zedek Medical Center, Affiliated with the Hebrew University School of Medicine, Jerusaleml 91031, Israel.
Dov
D
Wengrower
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004724:Endoscopy; D016145:Endoscopy, Digestive System; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D041981:Gastrointestinal Tract / Q000000981:diagnostic imaging*; D006801:Humans; D033162:Incidental Findings; D007249:Inflammation; D008206:Lymphatic Diseases / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
Endoscopy; Gastrointestinal tract; Malignancy; Positron emission tomography with fluorodeoxyglucose; Unexpected findings