PET/CT incidental detection of second tumor in patients investigated for pancreatic neoplasms

Abstract

BackgroundPositron Emission Tomography/computed tomography (PET/CT) is an imaging technique which has a role in the detection and staging malignancies (both in first diagnosis and follow-up). The finding of an unexpected region of FDG (Fluorodeoxyglucose) uptake can occur when performing whole-body FDG-PET, raising the possibility of a second primary tumor. The aim of this study was to evaluate our experience of second primary cancer incidentally discovered during PET/CT examination performed for pancreatic diseases, during the initial work-up or follow-up after surgical resection.MethodsIn this study, a retrospective evaluation of a prospectively collected data base was performed. Three hundred ninety- nine patients with pancreatic pathology were evaluated by whole body PET/CT imaging from January 2004 to December 2014. Among them, 348 patients were scanned before surgical resection and 51 during the course of their follow-up (pancreatic cancer). Median follow-up time was 29 months (range 14-124).ResultsFifty-six patients (14%) had incidental uptake of FDG in their organs: 31 patients had focal uptake and 25 showed diffuse with or without focal uptake. All patients with focal uptake were investigated, and invasive malignancy was diagnosed in 22 patients: 14 colon, 4 lung, 1 larynx, 1 urothelial, 1 breast cancer, and 1 colon metastasis from pancreatic cancer. Twenty patients underwent resection, and 6 endoscopic removal of colonic polyps. Three patients were not operated for advanced disease, and two patients did not show any pathology (PET/CT false positive). Of the 10 patients investigated for diffuse uptake, no malignancy was found; none of these patients developed a second cancer during the follow-up.ConclusionsAs in other malignancies, unexpected FDG uptake can occur in patients having PET/CT investigation for pancreatic diseases. Focal uptake is likely to be a malignancy and deserves further investigations, although the stage and the poor prognosis of primary pancreatic cancer should be kept in mind. Some selected patients may benefit from the aggressive treatment of incidental lesions and show survival benefit.

Quadruple Multiple Primary Malignancies: Early Detection of Second Primary Malignancy by Esophagogastroduodenoscopy/Colonoscopy Is Crucial for Patients with Classic Kaposi’s Sarcoma

“…To detect SPMs or visceral KS in patients with KS, EGD/CS is a more useful approach than positron-emission tomography (PET)/CT. PET/CT has been well-reported to detect SPMs in various body sites of patients with primary cancer [42][43][44][45]. However, we recommend EGD/CS for these patients for the following reasons: First, PET/CT may overlook SPMs because it potentially overlooks small-sized upper gastrointestinal cancer and colon cancer.…”

Incidentalomas of the prostate detected by 18-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography

“…4,6 The rate of CaP detected in FDG PET prostate incidentalomas is variable in prior reports. 1 Han et al evaluated 87% of patients with a prostate incidentaloma and found that 5.4% represented CaP. 12 Bertagna et al evaluated 22.5% of patients with PSA and biopsy and found CaP in 55.5% of evaluated cases, or 12.5% of the overall cohort.…”

“…Incidentalomas are commonly observed, occurring in approximately 10-14% of FDG PET scans. 1,2 Some of these incidentalomas are located within the prostate in the absence of known CaP. The rate of prostate incidentaloma on FDG PET has been reported in two series as 0.086% 9 and 1.4%.…”

“…The shift towards an increase in aerobic glycolysis, known as the Warburg effect, is a well characterized metabolic derangement in cancer. 1 18-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography (FDG PET) detects this increase in glycolysis and, as such, is routinely used in the diagnosis and surveillance of many cancers, including melanoma, lung cancer, squamous cell carcinoma of the head and neck, and lymphoma. 1,2 Prostate cancer (CaP), however, does not routinely experience the Warburg effect and FDG PET is not part of the routine staging of CaP.…”

“…1 18-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography (FDG PET) detects this increase in glycolysis and, as such, is routinely used in the diagnosis and surveillance of many cancers, including melanoma, lung cancer, squamous cell carcinoma of the head and neck, and lymphoma. 1,2 Prostate cancer (CaP), however, does not routinely experience the Warburg effect and FDG PET is not part of the routine staging of CaP. [3][4][5][6][7] An investigation of FDG PET in localized CaP revealed 51.9% sensitivity and 75.7% specificity in the context of an elevated prostate specific antigen (PSA).…”