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

Positron 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

Multiple large osteolytic lesions in a patient with systemic mastocytosis: a challenging diagnosis

Patients with advanced variants of Systemic Mastocytosis may develop destructive bone lesions when massive mast cell (MC) infiltrates are present. Finding of large osteolyses in indolent systemic mastocytosis, typically characterized by low MC burden, should prompt investigations for an alternative explanation

Comparison of International Consensus Guidelines versus 18-FDG PET in detecting malignancy of intraductal papillary mucinous neoplasms of the pancreas.

OBJECTIVE: To assess the reliability of the International Consensus Guidelines (ICG) and 18-fluorodeoxyglucose positron emission tomography (PET) in distinguishing benign from malignant intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. BACKGROUND: Since 2006 the ICG have been used to choose immediate surgery or surveillance for IPMN patients, but their low specificity increases the number of benign IPMNs that undergo resective surgery. PET has proved highly sensitive and specific in detecting malignancy in cystic neoplasms of the pancreas, including IPMNs. METHODS: Patients suspected with IPMNs of the pancreas seen at our Department from January 1989 to July 2010 were identified and classified as cases of main duct, mixed type and branch type IPMN. The indication for resection or surveillance was verified a posteriori for all patients according to the ICG. PET was considered positive for a Standardized Uptake Value 652.5. Surveillance included clinical examination, laboratory tests, CA 19-9 serum levels, and computed tomography and/or magnetic resonance and magnetic resonance cholangiopancreatography every 6 months for 2 years and yearly thereafter. Endoscopic ultrasound was rarely performed. PET was repeated in clinically or radiologically suspect cases, or if tumor markers increased. RESULTS: Sixty-one main duct or mixed type and 101-branch type IPMNs were included in the study. A histological diagnosis was available for 81 of 162 patients, missing for 1 locally advanced IPMN, whereas 62 patients are under surveillance and it proved impossible to contact 18. Conservative surgery was performed in 16 of 68 patients with benign IPMNs. The sensitivity, specificity, positive and negative predictive value, and accuracy of the ICG in detecting malignancy were 93.2, 22.2, 59.4, 72.7, and 61.2, whereas for PET they were 83.3, 100, 100, 84.6, and 91.3. CONCLUSIONS: PET is more accurate than the ICG in distinguishing benign from malignant (invasive and noninvasive) IPMNs. Prophylactic IPMN resection in young patients fit for surgery should be guided by the ICG, whereas PET should be performed in older patients, cases at increased surgical risk, or when the feasibility of parenchyma-sparing surgery demands a reliable preoperative exclusion of malignancy

Tumor Relapse after Pancreatic Cancer Resection is Detected Earlier by 18-FDG PET than by CT.

INTRODUCTION: Pancreatic cancer recurrence is often difficult to detect by conventional imaging. Our aim was to evaluate the impact of fluorodeoxyglucose-positron emission tomography (FDG-PET) in the diagnosis of recurrent pancreatic cancer. METHODS: One-hundred thirty-eight patients were followed after resection for pancreatic cancer. Sixty-six underwent only CT and were excluded. Seventy-two patients also had FDG-PET. Recurrent patients were divided in two groups: group-1, CT positive and group 2, CT non diagnostic, FDG-PET positive. Characteristics and survival curves of the two groups were compared. Significance was set at p < 0.05. RESULTS: Overall, tumors recurred in 63 of 72 (87.5%) patients; two patients had a second cancer resected, thanks to FDG-PET. Tumor relapse was detected by CT in 35 patients and by FDG-PET in 61. Prognostic factors were similar in groups 1 and 2. Five out of 35 group 1 patients underwent surgery (two R0, two bypass, and one exploratory). Ten out of 28 group 2 patients underwent surgery (four R0, two R2, two bypass, and two exploratory). FDG-PET influenced treatment strategies in 32 of 72 patients (44.4%). Group 2 patients survived longer (P = 0.09), but the difference was not significant. Disease-free survival was similar in groups 1 and 2. CONCLUSION: Tumor relapse is detected earlier by FDG-PET than by CT. FDG-PET can help select the best candidates for surgical exploration, although the real benefit is still to be defined. It influences treatment strategies in a significant percentage of patients. An earlier diagnosis did not influence survival due to the lack of effective therapies

Clinical usefulness of 18-fluorodeoxyglucose positron emission tomography in the management of patients with nonpancreatic periampullary neoplasms.

BACKGROUND: 18-Fluorodeoxyglucose positron emission tomography (18-FDG PET) has been investigated for the diagnosis and staging of gastrointestinal malignancies including pancreatic adenocarcinoma. The aim of this study was to examine the clinical usefulness of 18-FDG PET in the diagnosis and follow-up evaluation of patients with periampullary neoplasms. METHODS: Twenty-five patients underwent whole-body 18-FDG PET and abdominal computed tomography (CT). Pathologic confirmation was obtained in all patients by surgical resection or biopsy examination. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value (SUV). Positivity was assumed when a focal uptake occurred with an SUV of 2.5 or greater. RESULTS: Between January 1998 and December 2003, 14 ampullary, 7 bile duct, and 4 duodenal tumors were included in the study. PET showed increased focal uptake in 22 patients (88%): 11 of 14 (79%) ampullary tumors, and 100% of bile duct and duodenal tumors. PET showed a focal uptake in 11 of 12 patients without detectable mass at CT scan, and lymph node metastases in 6 patients. An SUV value of 2.7 discriminated adenomas or noninvasive cancers (n = 6) from invasive malignancies (n = 14). Follow-up evaluation including CT scan and PET was performed in 12 patients: PET showed recurrent disease not seen by CT in 4 patients, confirmed CT findings in 6 patients, and showed an unsuspected primary lung cancer in 1 patient and colon cancer in another patient. CONCLUSIONS: 18-FDG PET is very sensitive for detecting periampullary neoplasms. It may be useful to differentiate benign or borderline lesions from invasive tumors when no mass has been identified by traditional imaging. Finally, it is very useful in the follow-up evaluation of resected patients to identify recurrent disease or other malignancies