Differential diagnosis of gallbladder cancer using positron emission tomography with fluorine-18-labeled fluoro-deoxyglucose (FDG-PET)

Quarter-Century PET/Computed Tomography Transformation of Oncology: Hepatobiliary and Pancreatic Cancer

[18F] Fluorodeoxyglucose (18F-FDG) PET/CT can improve the staging accuracy and clinical management of patients with hepatobiliary and pancreatic cancers, by detection of unsuspected metastases. 18F-FDG PET/CT metabolic parameters are valuable in predicting treatment response and survival. Metabolic response on 18F-FDG PET/CT can predict preoperative pathologic response to neoadjuvant therapy in patients with pancreatic cancer and determine prognosis. Several novel non-FDG tracers, such as 68Ga prostate-specific membrane antigen (PSMA) and 68Ga-fibroblast activation protein inhibitor (FAPI) PET/CT, show promise for imaging hepatobiliary and pancreatic cancers with potential for radioligand therapy.

Xanthogranulomatous cholecystitis in a patient with ulcerative colitis and primary sclerosing cholangitis: A case report

Chronic gallbladder disease due to xanthogranulomatous cholecystitis is uncommon, and its symptoms are generally vague. While there is no firm evidence to link xanthogranulomatous cholecystitis to primary sclerosing cholangitis or ulcerative colitis. The patient is a 41-year-old male with a history of ulcerative colitis, primary sclerosing cholangitis, and biliary stenting who complained of symptoms of anorexia, jaundice, and pruritus. In the initial ultrasound exam, there was evidence of intrahepatic and extra-hepatic bile duct dilation along with a significant and mass-like circumferential thickening of the gallbladder wall. Magnetic resonance cholangiopancreatography was performed for further evaluation, which indicated increased gallbladder wall thickness, containing multiple T2 hyper-signal nodules while the mucosal layer was intact. There was also a filling defect in the common bile duct's distal portion. These findings matched a xanthogranulomatous cholecystitis diagnosis and a possibly malignant lesion in the distal of the common bile duct. The patient ultimately had a cholecystectomy, and pathology findings confirmed the diagnosis of xanthogranulomatous cholecystitis. Biopsy specimens obtained from the distal of the common bile duct lesion were microscopically identified as intramucosal adenocarcinoma. In patients with a history of primary sclerosing cholangitis who present with nonspecific symptoms suggesting chronic gallbladder disease and radiologic evidence of circumferential gallbladder wall thickening containing intramural nodules and intact mucosa, xanthogranulomatous cholecystitis should be kept in mind.

Multiparameter diagnostic model based on 18F-FDG PET metabolic parameters and clinical variables can differentiate nonmetastatic gallbladder cancer and cholecystitis

OBJECTIVE

To evaluate the diagnostic value of a multiparameter model based on ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) metabolic parameters and clinical variables in differentiating nonmetastatic gallbladder cancer (GBC) from cholecystitis.

PATIENTS AND METHODS

In total, 122 patients (88 GBC nonmetastatic patients and 34 cholecystitis patients) with gallbladder space-occupying lesions who underwent ¹⁸F-FDG PET/CT were included. All patients received surgery and pathology, and baseline characteristics and clinical data were also collected. The metabolic parameters of ¹⁸F-FDG PET, including SUVmax (maximum standard uptake value), SUVmean (mean standard uptake value), SUVpeak (peak standard uptake value), MTV (metabolic tumour volume), TLG (total lesion glycolysis) and SUVR (tumour-to-normal liver standard uptake value ratio), were evaluated. The differential diagnostic efficacy of each independent parameter and multiparameter combination model was evaluated using the receiver operating characteristic (ROC) curve. The improvement in diagnostic efficacy using a combination of the above multiple parameters was evaluated by integrated discriminatory improvement (IDI), net reclassification improvement (NRI) and bootstrap test. Decision curve analysis (DCA) was used to evaluate clinical efficacy.

RESULTS

The ROC curve showed that SUVR had the highest diagnostic ability among the ¹⁸F-FDG PET metabolic parameters (area under the curve [AUC] = 0.698; sensitivity = 0.341; specificity = 0.971; positive predictive value [PPV] = 0.968; negative predictive value [NPV] = 0.363). The combined diagnostic model of cholecystolithiasis, fever, CEA > 5 ng/ml and SUVR showed an AUC of 0.899 (sensitivity = 0.909, specificity = 0.735, PPV = 0.899, NPV = 0.758). The diagnostic efficiency of the model was improved significantly compared with SUVR. The clinical efficacy of the model was confirmed by DCA.

CONCLUSIONS

The multiparameter diagnostic model composed of ¹⁸F-FDG PET metabolic parameters (SUVR) and clinical variables, including patient signs (fever), medical history (cholecystolithiasis) and laboratory examination (CEA > 5 ng/ml), has good diagnostic efficacy in the differential diagnosis of nonmetastatic GBC and cholecystitis.

A Review of the Etiology and Epidemiology of Gallbladder Cancer: What You Need to Know

Gallbladder cancer (GBC) is the sixth most prevalent cancer of the gastrointestinal system but the most prevalent cancer of the biliary tract. This tumor is a highly fatal condition. The importance of early diagnosis cannot be overstated because GBC develops quietly with late detection. Several genetic and environmental variables have been associated with the onset of GBC. Cholelithiasis and chronic inflammation from the biliary tract and parasite infections are prime examples of environmental factors that significantly influence the development of GBC. Abnormal pancreaticobiliary duct junction and biliary cysts are examples of congenital causes. In the past decade, new imaging technologies and a more radical and aggressive surgical approach have improved patient outcomes and aided prolonged survival for GBC patients. This review article focuses on the epidemiology of GBC, its risk factors, and clinical characteristics.

Malignant Lymphoma Diagnosed as Gallbladder Carcinoma on 18F-FDG PET/CT

ABSTRACT

Extranodal primary lymphoma of gallbladder is extremely rare. We report a 48-year-old woman initially diagnosed as gallbladder carcinoma with lymph nodes metastases by contrast-enhanced CT and MRI. Meanwhile the images of 18F-FDG PET/CT highly suggested gallbladder carcinoma due to the necrosis in one of the enlarged lymph nodes. However, it was proved to be diffuse large B-cell lymphoma by the histopathological diagnosis.

Clinical value of diffusion-weighted MRI for differentiation between benign and malignant gallbladder disease: a systematic review and meta-analysis

BACKGROUND

Radiological differentiation between benign and malignant gallbladder disease is important but remains challenging. Furthermore, the clinical value of diffusion-weighted imaging (DWI) remains unclear.

PURPOSE

To determine the value of DWI in discriminating benign from malignant gallbladder disease by conducting a systematic review and meta-analysis.

MATERIAL AND METHODS

The literature was systematically searched. Studies analyzing diagnostic value of DWI in gallbladder disease with histopathology or follow-up as reference standard were included. Study selection and data extraction were done by two reviewers independently. Methodological quality was assessed using the QUADAS-2 tool. Sensitivity and specificity were calculated and displayed in a forest plot. A sensitivity analysis was performed in case of outliers. Pooled sensitivity and specificity of DWI were plotted on a hierarchical summary receiver operating characteristic curve. If available, the added value of DWI to conventional magnetic resonance imaging (MRI) sequences was analyzed.

RESULTS

Out of 2456 articles, eight studies fulfilled the inclusion criteria; 592 patients with 221 malignant lesions were included. Pooled sensitivity and specificity rates were 0.87 and 0.84, respectively. In two studies, diagnostic accuracy rates improved after adding DWI to conventional MRI (64% and 75% for conventional MRI vs. 89% and 94% after combining conventional MRI with DWI). In another study, the area under the curve increased from 0.92 to 0.95.

CONCLUSION

DWI appears to be an accurate imaging technique in discriminating benign from malignant gallbladder disease. To achieve optimal patient care, it should be part of multiparametric MRI and should be combined with other imaging modalities.

An Important Gallbladder Pathology Mimicking Gallbladder Carcinoma: Xanthogranulomatous Cholecystitis: A Single Tertiary Center Experience

BACKGROUND

Xanthogranulomatous cholecystitis (XGC) is an uncommon, focal, or diffuse destructive inflammatory disease of the gallbladder mimicking or being together with the gallbladder carcinoma. This study aimed to evaluate the diagnosis, treatment, and outcomes of patients with XGC as a single tertiary center experience in the light of literature.

MATERIALS AND METHODS

Data about 34 patients with XGC identified after evaluating 2212 cholecystectomy specimens between January 2013 and December 2018 in a single tertiary center were documented to determine demographics (sex, age), clinical symptoms and findings, biochemical and imaging clues and operative findings, duration of hospitalization, postoperative complications, and histopathologic results.

RESULTS

Thirty-four patients with XGC were evaluated (17 male and 17 female patients with a mean age of 53; range, 25 to 78). Preoperative diagnosis was chronic calculous cholecystitis in 5 patients, cholelithiasis in 12 cases, acute calculous cholecystitis in 16 and emphysematous cholecystitis in 1 patient. Ultrasound was performed in all patients, computerized tomography in 11, contrast-enhanced magnetic resonance imaging in 9, and magnetic resonance cholangiopancreatography in 7 patients. None of the patients were diagnosed preoperatively. All patients received laparoscopic cholecystectomy, among whom 9 were converted to open. Partial cholecystectomy was performed in 1 patient. One patient with gallbladder adenocarcinoma was treated with radical cholecystectomy. XGC has nonspecific clinical and radiologic findings; thus, preoperative diagnosis is generally absent. Open cholecystectomy is the recommended treatment modality. Conversion to open is frequently necessary after laparoscopy. Complete cholecystectomy is the ultimate goal; however, partial cholecystectomy may be preferred to protect the structures of the hepatic hilum. Preoperative imaging studies (ultrasound or computerized tomography) of 34 patients showed a gallbladder stone in 18 patients, microlithiazis in 12 patients, sludge in 10 patients, and gallbladder sclerosis in 5 patients.

CONCLUSIONS

Diagnosis of XGC and differentiation from gallbladder carcinoma may be difficult through preoperative or peroperative studies, even imaging is useful; the definitive diagnosis depends exclusively on pathologic examination. The surgeon should be prepared for every possibility.

Locally advanced gallbladder cancer: a review of the criteria and role of imaging

Gallbladder carcinoma (GBC) is among one of the gastrointestinal malignancies with extremely dismal prognosis. This is due to the advanced stage at presentation. Majority of the patients with GBC are not considered candidates for surgery because of the locally advanced disease or metastases. However, with the accumulating evidence regarding the role of neoadjuvant chemotherapy, there is a need to correctly identify a subset of patients with locally advanced GBC who will benefit maximally from neoadjuvant chemotherapy and will be successfully downstaged to receive curative (R0) surgery. In this context, there is a lack of consensus and different groups have resorted to criteria for locally advanced disease eligible for neoadjuvant chemotherapy based on personal or institutional experiences. Imaging plays a critical role in the evaluation of patients with GBC as it helps stratify patients into resectable and unresectable. Imaging also has the potential to identify patients with locally advanced GBC and hence facilitate neoadjuvant chemotherapy and improve outcomes. In this review, we evaluate the various criteria for locally advanced GBC and the role of imaging in this scenario.

Gallbladder polyps: evolving approach to the diagnosis and management

Gallbladder (GB) polyp is a mucosal projection into the GB lumen. With increasing health awareness, GB polyps are frequently found using ultrasonography during health screening. The prevalence of GB polyps ranges between 1.3% and 9.5%. Most patients are asymptomatic and have benign characteristics. Of the nonneoplastic polyps, cholesterol polyps are most common, accounting for 60%-70% of lesions. However, a few polyps have malignant potential. Currently, the guidelines recommend laparoscopic cholecystectomy for polyps larger than 1 cm in diameter due to their malignan potential. The treatment algorithm can be influenced by the size, shape, and numbers of polyps, old age (>50 years), the presence of primary sclerosing cholangitis, and gallstones. This review summarizes the commonly recognized concepts on GB polyps from diagnosis to an algorithm of treatment.

Xanthogranulomatous cholecystitis: a review of 31 patients

BACKGROUND

Xanthogranulomatous cholecystitis (XGC) is a rare inflammatory gallbladder disease which is difficult to diagnose and treat; XGC may be confused with gallbladder cancer. The present study aimed to evaluate the clinical and radiological features and surgical outcomes, with the aim to determine the appropriate treatment approaches for XGC.

METHODS

This retrospective study analyzed the clinical characteristics, intraoperative findings, and postoperative outcomes of 31 patients (2.0%) who were diagnosed with XGC based on histopathological findings among 1513 patients who underwent cholecystectomy at our hospital between January 2010 and July 2019.

RESULTS

Preoperative ultrasonography and computed tomography findings indicated acute cholecystitis, chronic cholecystitis, and suspicious XGC in 26 (83.9%) patients with thickening of the gallbladder wall and suspicious gallbladder cancer in 5 (16.1%) patients. Abdominal pain and jaundice were observed in 18 (58.1%) patients and 5 (16.1%) patients, respectively. Biliary drainage before surgery was performed in 21 (67.7%) patients. Laparoscopic cholecystectomy, which was performed in 23 (74.2%) patients, was converted to open cholecystectomy in 12 (52.2%) of these 23 patients. Among the patients with other diseases treated during the study period, laparoscopic cholecystectomy was performed in 1377 patients and converted to open surgery in 71 (5.2%) patients. Five patients with suspicious gallbladder cancer underwent open surgery. In these patients, intraoperative frozen section analysis was useful in distinguishing between XGC and gallbladder cancer and was important in avoiding unnecessarily extended surgery.

CONCLUSION

Laparoscopic cholecystectomy for XGC is possible, but often difficult due to severe inflammation. The frequency of conversion to open surgery is higher in patients with XGC than those with other forms of cholecystitis. XGC may resemble gallbladder cancer based on the diagnostic imaging findings, and intraoperative frozen section analysis is essential to avoid unnecessarily extended surgery.

Radio-pathological Correlation of 18F-FDG PET in Characterizing Gallbladder Wall Thickening

AIM

Thick-walled gallbladder is difficult to characterize on conventional imaging. 18F-FDG PET was used to differentiate benign and malignant wall thickness and compared with histopathology.

METHODS

Thirty patients with gallbladder (GB) wall thickening (focal > 4 mm and diffuse > 7 mm), underwents uspected on  ultrasound, or CT scan, and underwent 18F-FDG PET. Histopathology of the specimen was compared with imaging findings.

RESULTS

The mean age was 48.22 ± 31.33 years with a M:F 1:4 ratio. Twenty patients had diffuse and 10 had focal thickening. On 18F-FDG PET, lesion was benign in 12, malignant in 13, and indeterminate in 5. Histopathology was malignancy in 12; benign in 18-chronic cholecystitis in 11, xanthogranulomatous in 4, IgG4 related in 2, and polyp in 1. The mean GB wall thickness was 7.79 ± 3.59 mm (10.34 malignant and 6.10 in benign, p = 0.001). At a cutoff of 8.5 mm, the sensitivity and specificity of detecting malignancy was 94% and 67%. The mean SUV uptake was 7.46 (benign 4.51, malignant 14.26, p = 0.0102). At a cutoff of 5.95, the sensitivity and specificity of detecting malignancy was 92% and 79%. For 18F-FDG PET, overall sensitivity was 91%, specificity 79%, PPV 77%, NPV 92%, and diagnostic accuracy was 84%.

CONCLUSION

18F-FDG PET is a reliable method of differentiation between benign and malignant thickening of the gallbladder particularly when wall thickness and SUV value is taken into account.

The Role of 18F-FDG PET/CT in staging of gallbladder carcinomas

BACKGROUND/AIMS

Gallbladder Carcinoma (GBC) is the most common and aggressive tumor of the biliary tract. Patients are typically diagnosed during advanced stages, and the mean overall survival is short. In our study, we aimed to demonstrate the uptake patterns of 18F-FDG PET/CT in GBC, as well as its association with survival and diagnostic value during the initial stage.

MATERIALS AND METHODS

Overall, 17 patients with GBC were retrospectively included in the study. 18F-FDG PET/CT study was performed for pretreatment staging. Two different standardized uptake values (SUVmax and SUVmean), metabolic tumor volume 40% (MTV40), and tumor lesion glycolysis (TLG) of the primary tumors were compared between the clinical and histopathological groups.

RESULTS

Of the 17 patients, 11 were women (64.7%), and 6 (35.3%) were men. The mean age of the patients was 69.7±8.8 years. 18F-FDG uptake was detected in all lesions. Mean SUVmax was calculated to be 15.4±13.7 (median=10.6, range=3.4-46.8). All distant metastases (52.9%) were detected in the liver. Semiquantitative metabolic parameters (SUVmax and SUVmean, MTV40, and TLG) obtained from patients with distant metastasis were not significantly higher than those without distant metastasis. Similar results were obtained in patients with and without nodal metastasis. No statistically significant intergroup difference was observed regarding metabolic parameters. However, a statistically significant negative correlation was observed between the patient's age and the SUVmax of the primary lesion and metastatic lymph nodes (r=-0.564, p=0.018). During 10.7±10.4 months of mean follow-up, the mean survival of patients with distant metastases (6.1±11.0 months) was significantly shorter than that of patients with no organ metastases (15.8±7.1 months).

CONCLUSION

In our study, distant metastases and age were observed to be crucial prognostic factors in patients with gallbladder carcinoma (GBC). In addition, we believe that 18F-FDG PET/CT imaging will help to stage the GBC, detect nodal and distant metastasis, and evaluate the metabolic state of gallbladder lesions.

18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) for patients with biliary tract cancer: Systematic review and meta-analysis

BACKGROUND & AIMS

The role of ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) in the diagnosis and staging of patients with biliary tract cancers (BTCs) remains controversial, so we aimed to provide robust information on the utility of ¹⁸FDG-PET in the diagnosis and management of BTC.

METHODS

This systematic review and meta-analysis explored the diagnostic test accuracy of ¹⁸FDG-PET as a diagnostic tool for diagnosis of primary tumour, lymph node invasion, distant metastases and relapsed disease. Subgroup analysis by study quality and BTC subtype were performed. Changes in management based on ¹⁸FDG-PET and impact of maximum standardised uptake values (SUVmax) on prognosis were also assessed. A random effects model was used for meta-analyses.

RESULTS

A total of 2,125 patients were included from 47 eligible studies. The sensitivity (Se) and specificity (Sp) of ¹⁸FDG-PET for the diagnosis of primary tumour were 91.7% (95% CI 89.8-93.2) and 51.3% (95% CI 46.4-56.2), respectively, with an area under the curve (AUC) of 0.8668. For lymph node invasion, Se was 88.4% (95% CI82.6-92.8) and Sp was 69.1% (95% CI 63.8-74.1); AUC 0.8519. For distant metastases, Se was 85.4% (95% CI 79.5-90.2) and Sp was 89.7% (95% CI86.0-92.7); AUC 0.9253. For relapse, Se was 90.1% (95% CI 84.4-94.3) and Sp was 83.5% (95% CI 74.4-90.4); AUC 0.9592. No diagnostic threshold effect was identified. Meta-regression did not identify significant sources of heterogeneity. Sensitivity analysis revealed no change in results when analyses were limited to studies with low risk of bias/concern. The pooled proportion of change in management was 15% (95% CI 11-20); the majority (78%) due to disease upstaging. Baseline high SUVmax was associated with worse survival (pooled hazard ratio of 1.79; 95% CI 1.37-2.33; p <0.001).

CONCLUSIONS

There is evidence to support the incorporation of ¹⁸FDG-PET into the current standard of care for the staging (lymph node and distant metastases) and identification of relapse in patients with BTC to guide treatment selection; especially if the identification of occult sites of disease would change management, or if diagnosis of relapse remains unclear following standard of care imaging. The role for diagnosis of the primary tumour remains controversial due to low sensitivity and ¹⁸FDG-PET should not be considered as a replacement for pathological confirmation in this setting.

LAY SUMMARY

A positron emission tomography (PET scan), using ¹⁸F-fluorodeoxyglucose (¹⁸FDG), can help doctors identify areas of cancer in the body by highlighting "hot spots". These hotspots may be cancerous (true positive) but may also be non-cancerous, like inflammation (false positive). We show that PET scans are useful to assess how far advanced the cancer is (by assessing spread to lymph glands and to other organs) and also to identify if the cancer has recurred (for example after surgery), thus helping doctors to make treatment decisions. However, a biopsy is still needed for the initial diagnosis of a biliary tract cancer, because of the high chance of a "false positive" with PET scans.

Strategies for Differentiating Gallbladder Carcinoma from Xanthogranulomatous Cholecystitis-a Tertiary Care Centre Experience

Xanthogranulomatous cholecystitis (XGC) is an uncommon variant of chronic cholecystitis, characterized by focal or diffuse destructive inflammatory process. The importance of XGC is that it mimics gallbladder carcinoma (GBC) both preoperatively and intra-operatively, since it can present with pericholecystic infiltration, hepatic involvement and lymphadenopathy. As a result of this misdiagnosis which is not infrequent, the patient may need to undergo an unnecessary radical cholecystectomy rather than only a cholecystectomy which is associated with greater morbidity and mortality. Patients who underwent gallbladder and gallbladder-related operations during period of 5 years between 2010 and 2014 were reviewed (n = 462). A comparison of clinical, biochemical, radiological and operative features were made between patients with carcinoma gallbladder (n = 101) and xanthogranulomatous cholecystitis (n = 22). Patient with a long history of recurrent abdominal pain with leucocytosis and who on imaging are found to have a diffusely thickened gallbladder wall (p < 0.01), with cholelithiasis, choledocholithiasis and sub-mucosal hypoattenuated nodules (p < 0.05) are likely to have XGC while those with anorexia, weight loss, focal thickening of the gallbladder wall on imaging (p < 0.01) and dense local organ infiltration are more likely to have GBC. The presence of lymph nodes on imaging and the loss of fat plane interface between the liver and gallbladder are not differentiating factors. Differentiating XGC from GBC in preoperative setting is necessary to avoid radical procedures being done for a benign process. Certain clinical, radiological and intra-operative features aid in differentiating these benign and malignant process. However, the definitive diagnosis still remains a histopathological examination to avoid radical resection in patients who have a benign condition.

A case report of wound site seeding following cholecystectomy for dysplastic gallbladder

Wound site metastasis following cholecystectomy is an uncommon but well recognised complication following laparoscopic surgery for unsuspected gallbladder carcinoma. We describe a case of implantation of dysplastic cells with subsequent malignant transformation at the incision site 3 years post-cholecystectomy for an inflamed gallbladder. Histopathological examination of this tumour confirmed adenocarcinoma of pancreatobiliary origin, possibly secondary to gallbladder cells implantation and subsequent carcinomatous change. Unlike previously reported cases, the present case has two unique features: Firstly, the histology of the resected gallbladder at the initial operation was that of a low-grade dysplasia and not carcinoma; and secondly, there was a long interval between initial surgery and subsequent development of the wound site tumour. This case highlights that careful handling of the specimen tissue intraoperatively is paramount as cells implanted in the wound site can survive and undergo malignant transformation. All new masses occurring along the surgical wound site should be followed up and investigated to exclude implanted tumours.

Evidence based management of polyps of the gall bladder: A systematic review of the risk factors of malignancy

BACKGROUND

There are no evidence-based guidelines to dictate when Gallbladder Polyps (GBPs) of varying sizes should be resected.

AIM

To identify factors that accurately predict malignant disease in GBP; to provide an evidence-based algorithm for management.

METHODS

A systematic review following PRISMA guidelines was performed using terms "gallbladder polyps" AND "polypoid lesion of gallbladder", from January 1993 and September 2013. Inclusion criteria required histopathological report or follow-up of 2 years. RTI-IB tool was used for quality analysis. Correlation with GBP size and malignant potential was analysed using Euclidean distance; a logistics mixed effects model was used for assessing independent risk factors for malignancy.

RESULTS

Fifty-three articles were included in review. Data from 21 studies was pooled for analysis. Optimum size cut-off for resection of GBPs was 10 mm. Probability of malignancy is approximately zero at size <4.15 mm. Patient age >50 years, sessile and single polyps were independent risk factors for malignancy. For polyps sized 4 mm-10 mm, a risk assessment model was formulated.

CONCLUSIONS

This review and analysis has provided an evidence-based algorithm for the management of GBPs. Longitudinal studies are needed to better understand the behaviour of polyps <10 mm, that are not at a high risk of malignancy, but may change over time.

Xanthogranulomatous cholecystitis: Difficulty in differentiating from gallbladder cancer

AIM: To compare cases of xanthogranulomatous cholecystitis (XGC) and advanced gallbladder cancer and discuss the differential diagnoses and surgical options.

METHODS: From April 2000 to December 2013, 6 XGC patients received extended surgical resections. During the same period, 16 patients were proven to have gallbladder (GB) cancer, according to extended surgical resection. Subjects chosen for analysis in this study were restricted to cases of XGC with indistinct borders with the liver as it is often difficult to distinguish these patients from those with advanced GB cancer. We compared the clinical features and computed tomography findings between XGC and advanced GB cancer. The following clinical features were retrospectively assessed: age, gender, symptoms, and tumor markers. As albumin and the neutrophil/lymphocyte ratio (NLR) are prognostic in several cancers, we compared serum albumin levels and the NLR between the two groups. The computerized tomography findings were used to compare the two diseases, determine the coexistence of gallstones, the pattern of GB thickening (focal or diffuse), the presence of a hypoattenuated intramural nodule, and continuity of the mucosal line.

RESULTS: Based on the preoperative image findings, we suspected GB carcinoma in all cases including XGC in this series. In addition, by pathological examination, we found that the group of patients with XGC developed inflammatory disease after surgery. Patients with XGC tended to have abdominal pain (4/6, 67%). However, there was no significant difference in clinical symptoms, including fever, between the two groups. Serum albumin and NLR were also similar in the two groups. Serum tumor markers, such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), tended to increase in patients with GB cancer. However, no significant differences in tumor markers were identified. On the other hand, gallstones were more frequently observed in patients with XGC (5/6, 83%) than in patients with GB cancer (4/16, 33%) (P = 0.0116). A hypoattenuated intramural nodule was found in 3 patients with XGC (3/6, 50%), but in only 1 patient with GB cancer (1/16, 6%) (P = 0.0024). The GB thickness, continuous mucosal line, and bile duct dilatation showed no significant differences between XGC and GB cancer.

CONCLUSION: Although XGC is often difficult to differentiate from GB carcinoma, it is possible to obtain an accurate diagnosis by careful intraoperative gross observation, and several intraoperative frozen sections.

Role of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography in gastrointestinal cancers

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a routine imaging modality for many malignancies and its use is currently increasing. In the present review article, we will summarize the evidence for FDG-PET/CT use in digestive cancers (excluding neuroendocrine tumours), and review the existing recommendations. While PET/CT is nowadays considered to be an important tool in the initial workup of oesophageal and anal cancers, new data are emerging regarding its use in assessing therapeutic efficacy, radiotherapy treatment planning, and detection of recurrence in case of isolated tumour marker elevation. Moreover, PET/CT may help decision making by detecting distant metastatic sites especially in potentially resectable metastatic colorectal cancer and, to a lesser extent, in localized gastric and pancreatic cancers. Finally, incidental focal colonic FDG uptakes require exploration by colonoscopy, as they are often associated with premalignant or malignant lesions.

Gall bladder carcinoma: Aggressive malignancy with protean loco-regional and distant spread

The most common malignancy of biliary tract is gallbladder cancer (GBC) which is the third most common cancer in gastrointestinal tract. It is a lethal disease for most patients in spite of growing awareness and improved diagnostic techniques. GBC has a very poor prognosis and the 5 year survival rate is < 10%. Although etiology of the carcinoma of the gallbladder is still obscure, various factors have been implicated, cholelithiasis being the most frequent. The incidence of GBC worldwide is based on the gender, geography and ethnicity which suggest that both genetic and environmental factors can cause GBC. The major route of spread of gallbladder cancer (GC) is loco-regional rather than distant. It spreads by lymphatic, vascular, neural, intraperitoneal, and intraductal routes. Sonography is usually the most common imaging test to evaluate symptoms of biliary tract disease including suspected GC. With recent advances in imaging modalities like multi-detector computed tomography (CT) scanners, magnetic resonance imaging-positron emission tomography/CT diagnosis of gallbladder cancer has improved. Studies have also targeted molecular and genetic pathways. Treatment options have included extended and radical surgeries and adjuvant chemotherapy. This review article deals in detail with important aspects of carcinoma gallbladder and its manifestations and challenges. Role of various imaging modalities in characterization and accurate staging has been discussed. The loco-regional spread of this aggressive malignancy is dealt explicitly.

Expression of GLUT-1 and GLUT-3 in xanthogranulomatous cholecystitis induced a positive result on ¹⁸F-FDG PET: report of a case

Although several reports have revealed that fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) is useful for differentiating between benign and malignant lesions in the gallbladder, the positive results of (18)F-FDG PET are not specific for malignancy because (18)F-FDG is also accumulated in inflammatory lesions. It is known that the most important pathway for (18)F-FDG to enter the cell body is mediated by the facilitative glucose transporter-1 (GLUT-1) through GLUT-3. We herein present a case of xanthogranulomatous cholecystitis (XGC) with a positive result on (18)F-FDG PET. In this case, GLUT-1 and GLUT-3 were both positively expressed in inflammatory cells at the gallbladder wall of XGC and this is the first report to reveal GLUT expression in XGC. This report reveals that surgeons should carefully consider the appropriate treatment of gallbladder tumor, even with a positive result on (18)F-FDG PET.

Impact of pre-operative positron emission tomography in gallbladder cancer

BACKGROUND

Current pre-operative staging methods for gallbladder cancer (GBC) are suboptimal in detecting metastatic disease. Positron emission tomography (PET) may have a role but data are lacking.

METHODS

Patients with GBC and PET assessed by a hepatobiliary surgeon in clinic between January 2001 and June 2013 were retrospectively reviewed. Computed tomography (CT)/magnetic resonace imaging (MRI) were correlated with PET scans and analysed for evidence of metastatic or locally unresectable disease. Medical records were reviewed to determine if PET scanning was helpful by preventing non-therapeutic surgery or enabling resection in patients initially deemed unresectable.

RESULTS

There were 100 patients including 63 incidental GBC. Thirty-eight patients did not proceed to surgery, 35 were resected and 27 patients were explored but had unresectable disease. PET was positive for metastatic disease in 39 patients (sensitivity 56%, specificity 94%). Five patients definitively benefitted from PET: in 3 patients PET found disease not seen on CT, and 2 patients with suspicious CT findings had negative PET and successful resections. In a further 12 patients PET confirmed equivocal CT findings. Three patients had additional invasive procedures performed owing to PET avidity in other sites. Utility of PET was higher in patients with suspicious nodal disease on CT [odds ratio (OR) 7.1 versus no nodal disease, P = 0.0004], and in patients without a prior cholecystectomy (OR 3.1 versus post-cholecystectomy, P = 0.04).

CONCLUSION

Addition of PET to conventional cross-sectional imaging has a modest impact on management pre-operatively particularly in patients without a prior cholecystectomy and to confirm suspicious nodal disease on CT.

Xanthogranulomatous cholecystitis mimicking gallbladder cancer

Xanthogranulomatous cholecystitis (XGC) is a benign, uncommon variant of chronic cholecystitis characterised by focal or diffuse destructive inflammatory process of the gallbladder (GB). Macroscopically, it appears like yellowish tumour-like masses in the wall of the GB. This article reports on a 74-year-old woman with XGC mimicking GB cancer.

Is there any role of positron emission tomography computed tomography for predicting resectability of gallbladder cancer?

The role of integrated (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography computed tomography (PET-CT) is uncertain in gallbladder cancer. The aim of this study was to show the role of PET-CT in gallbladder cancer patients. Fifty-three patients with gallbladder cancer underwent preoperative computed tomography (CT) and PET-CT scans. Their medical records were retrospectively reviewed. Twenty-six patients underwent resection. Based on the final outcomes, PET-CT was in good agreement (0.61 to 0.80) with resectability whereas CT was in acceptable agreement (0.41 to 0.60) with resectability. When the diagnostic accuracy of the predictions for resectability was calculated with the ROC curve, the accuracy of PET-CT was higher than that of CT in patients who underwent surgical resection (P=0.03), however, there was no difference with all patients (P=0.12). CT and PET-CT had a discrepancy in assessing curative resection in nine patients. These consisted of two false negative and four false positive CT results (11.3%) and three false negative PET-CT results (5.1%). PET-CT was in good agreement with the final outcomes compared to CT. As a complementary role of PEC-CT to CT, PET-CT tended to show better prediction about resectability than CT, especially due to unexpected distant metastasis.

A case of xanthogranulomatous cholecystitis suspected to be adenocarcinoma based on the intraoperative peritoneal washing cytology

INTRODUCTION

Xanthogranulomatous cholecystitis (XGC) is a variant of chronic cholecystitis. XGC remains difficult to distinguish from gallbladder cancer radiologically and macroscopically.

PRESENTATION OF CASE

A 63-year-old female was referred to our hospital because of a gallbladder tumor. Abdominal CT and MRI revealed a thickened gallbladder that had an obscure border with the transverse colon. FDG-PET showed a high uptake of FDG in the gallbladder. Therefore, under the preoperative diagnosis of an advanced gallbladder cancer with invasion to the transverse colon, a laparotomy was performed. Because adenocarcinoma was suspected based on the intraoperative peritoneal washing cytology (IPWC), cholecystectomy and partial transverse colectomy were performed instead of radial surgery. However, the case was proven to be XGC with no malignant cells after the operation.

DISCUSSION

In patients with gallbladder cancer who underwent surgery in our institute from 2000 to 2009, the prognosis after the operation of patients with only positive IPWC tended to be better than that of patients with definitive peritoneal disseminated nodules. It is true that in some cases, it is difficult to differentiate XGC from gallbladder carcinoma pre- and intra-operatively.

CONCLUSION

Surgical procedures should be selected based on the facts that there are long-term survivors with gallbladder cancer diagnosed with positive IPWC, and that some patients with XGC are initially diagnosed to have carcinoma by IPWC, as was seen in our case.

Gallbladder cancer revealed by an endobiliary tumor thrombus

Common bile duct neoplastic thrombosis is rare and can cause jaundice in case of gallbladder cancer (GBC). We report the case of a 45-year-old man with GBC located in the fundus associated with a malignant endobiliary thrombus. A surgical procedure has been performed, including segmentectomy 4b+5 with common bile duct resection with Roux-en-Y hepaticojejunostomy. Postoperative courses were uneventful and the patient is alive at 15 months.

Ability of FDG-PET/CT in the detection of gallbladder cancer

PURPOSE

To assess the value of FDG-PET/CT in the evaluation of gallbladder carcinomas (GBC).

METHODS

A prospective cohort of patients with suspicion of or confirmed GBC was studied with FDG-PET/CT. Diagnostic accuracy parameters were calculated in comparison with pathology and/or the clinical course of patients. Clinical impact of PET/CT imaging was estimated.

RESULTS

Forty-nine patients were enrolled (34 malignant tumors, 15 benign lesions; 37 staging, 12 restaging). Overall diagnostic accuracy was 95.9% for the diagnosis of the primary lesion, 85.7% for lymph node involvement and 95.9% for metastatic disease. Mean SUVmax in malignant gallbladder lesions was 7.92 ± 6.25 Analysis of ROC curves showed a SUVmax cut-off value of 3.62 for malignancy (S: 78.1%; Sp: 88.2%). Diagnostic accuracy in the restaging group reached 100%. FDG-PET/CT changed the management of 22.4% of the population.

COMMENTS

Diagnosis of malignancy or benignity of suspicious gallbladder lesions is accurately made with FDG PET/CT, allowing a precise staging of GBC due to its ability to identify unsuspected metastatic disease. SUVmax has a complementary role in addition to visual analysis.

Clinical impact of FDG PET-CT on management decisions for patients with primary biliary tumours

Objectives

To assess the impact on clinical management of introducing ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)-computed tomography (CT) in to the work-up of patients with primary and recurrent biliary malignancy.

Methods

Consecutive patients with primary biliary tumours undergoing FDG PET-CT at a single large tertiary referral centre between November 2007 and September 2010 were retrospectively analysed. Findings on FDG PET-CT compared with CT/magnetic resonance imaging (MRI) and impact on subsequent patient management were evaluated. Impact was divided into: (1) major—detection of occult disease or characterisation of indeterminate lesion(s) on CT/MRI; (2) minor—confirmation of suspected metastases seen on CT/MRI; (3) no impact.

Results

One hundred and eleven patients underwent 118 FDG PET-CT scans, including 30 with suspected gallbladder carcinoma and 81 with cholangiocarcinoma. Eighty-nine scans were performed for initial staging, five for restaging following neoadjuvant chemotherapy and 24 for suspected disease recurrence. In 33 cases (28 %), FDG PET-CT had a major impact on subsequent patient management (39 % gallbladder carcinoma, 26 % intrahepatic cholangiocarcinoma and 21 % extrahepatic cholangiocarcinoma). FDG PET-CT had a minor impact in 20 cases (17 %) and no impact in 65 cases (55 %).

Conclusions

By detecting occult metastatic disease and characterising indeterminate lesions, FDG PET-CT can have a major influence on clinical decision-making in primary and recurrent biliary malignancy.

Stepwise approach and surgery for gallbladder adenomyomatosis: a mini-review

BACKGROUND

Gallbladder adenomyomatosis (GBA) is a hyperplastic disease affecting the wall of the gallbladder, with some typical features. It has historically been considered a benign condition, nevertheless recent reports highlighted a potential role of GBA in predisposing to malignancies of the gallbladder.

DATA SOURCES

We reviewed the literature concerning GBA from its identification until July 2012. Owing to the relative rarity of the disease, studies often are case reports or case series. Thus we herein report a summary of the key-points concerning diagnosis and treatment of GBA, easily applicable in everyday practice, rather than a systematic review. Also, results are integrated with our recent experience.

RESULTS

In our experience, we observed a trend toward an increase of GBA during the last years, probably due to enhanced ultrasonographic technical advancements and physician's expertise. GBA has distinctive imaging features. Several recent reports highlight the potential risk of cancer associated with GBA; however the disease is still classified as a benign condition. Although its correlation with malignancy has not been demonstrated, it is prudent to recommend cholecystectomy in some cases. However, in selected asymptomatic patients, a wait-and-see policy is a viable alternative. We propose an algorithm, based on GBA pathological pattern (diffuse, segmental, localized or fundal), suitable for decision-making.

CONCLUSIONS

In symptomatic patients and if the diagnosis is doubtful, cholecystectomy is mandatory. Postponing surgery is an option to be offered to asymptomatic patients with low-risk GBA pattern who adhere to scheduled follow-ups.

Mycobacterial infection of the gallbladder masquerading as gallbladder cancer with a false positive pet scan

Isolated mycobacterial infection of gall bladder is an extremely rare entity. Only anecdotal reports are evident in the literature. A preoperative diagnosis of mycobacterial infection of gallbladder is therefore very difficult. The case of a 72-year-old male who underwent surgery for suspected gallbladder cancer is presented. The diagnosis of cancer was based on radiological findings and an abnormal uptake of fluorine-18-fluoro-2-deoxy-D-glucose (FDG) on positron emission tomography (PET) scan whilst being followed up for colorectal cancer. He underwent cholecystectomy and gallbladder bed resection. Histopathology was consistent with mycobacterial infection of the gallbladder.

High b-value diffusion-weighted magnetic resonance imaging for gallbladder lesions: differentiation between benignity and malignancy

BACKGROUND

Recently, the clinical application of diffusion-weighted magnetic resonance imaging (DWI) has been expanding to abdominal organs. However, only a few studies on gallbladder diseases have been published. The aim of this study was to evaluate the usefulness and limitations of high b-value DWI for gallbladder diseases.

METHODS

A total of 153 patients (mean age 60 ± 15 years, 78 males) who had undergone DWI for evaluating gallbladder wall thickening or polypoid lesions were included in this study. Of these 153 patients, 36 had gallbladder cancer and 117 had benign gallbladder diseases (67 chronic cholecystitis, 44 adenomyomatosis, four cholesterol polyp, one gallbladder adenoma, and one xanthogranulomatous cholecystitis). We evaluated the positive signal rate with DWI and the apparent diffusion coefficient (ADC) value of each disease.

RESULTS

The positive signal rate with DWI was significantly higher in gallbladder cancer (78 %) than in benign gallbladder diseases (22 %) (p < 0.001). The mean ADC value of gallbladder cancer was (1.83 ± 0.69) × 10(-3) mm(2)/s and that of benign gallbladder diseases was (2.60 ± 0.54) × 10(-3) mm(2)/s (p < 0.001). Benign gallbladder diseases with acute cholecystitis or a history of that had a higher positive signal rate with DWI (p < 0.001) and a lower ADC value (p = 0.018) than those without such conditions.

CONCLUSION

DWI can contribute to the improvement of the diagnostic capability for gallbladder wall thickening or polypoid lesions by compensating for weaknesses of other modalities by its many advantages, although cases with acute cholecystitis or such history sometimes show false-positive on DWI.

Diagnostic and prognostic role of laparoscopic staging for gallbladder carcinoma

BACKGROUND

The aim of this study was to evaluate the diagnostic and prognostic role of staging laparoscopy in gallbladder carcinoma (GBC).

METHODS

From January 2007 through December 2010, 79 GBC patients without evidence of metastatic disease on preoperative imaging underwent staging laparoscopy. Peritoneal and liver metastases were assessed by a single surgeon in a systematic manner. Resection rate, safety, and survival analysis were compared between the laparoscopy group and no laparoscopy group.

RESULTS

Disseminated disease was detected in 27 patients and no further surgery was performed; the overall accuracy for detecting unresectable disease was 67.5% (27/40), with 39 (75%) and 27 (51.9%) receiving resection and curative resection. In 203 GBC patients undergoing laparotomy, 90 (44.3%) and 53 (26.1%) patients received resection and curative resection; therefore, the resection rate and curative resection rate were significantly much higher in the laparoscopy group (p < 0.000).

CONCLUSIONS

Staging laparoscopy in GBC is sensitive in detecting disseminated disease and increases the curative resection rate, shortens the recovery time, and has no negative implications on overall survival; therefore, we suggest the routine use of staging laparoscopy in patients with GBC without evidence of disseminated disease on preoperative imaging.

Role of 18F-FDG PET/CT in detecting recurrent gallbladder carcinoma

AIM

The present study was aimed to determine the efficacy of integrated FDG PET/CT in patients with gallbladder cancer (GBC) with suspicion of recurrent disease.

METHODS

A total of 49 patients (male: 15, female: 34; median age: 52.5 years) with GBC underwent FDG PET/CT for suspected recurrence. A total of 62 PET/CT scans were acquired. Criteria for detection by PET/CT were both a positive FDG uptake and the correct anatomic localization of the tumor. The PET/CT findings were grouped as locoregional disease and metastatic disease. Results of PET/CT were compared with clinical and radiologic follow-up and/or histopathology. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Results of PET/CT were also compared with conventional imaging (CI) whenever available.

RESULTS

Of 62 PET/CT, 43 (69.4%) were positive and 19 (30.6%) were negative for recurrence. Of 43 positive scans, 41 were true positive and 2 were false positive. Among 19 negative PET/CT scans, 18 were true negative and 1 was false negative. PET/CT showed a sensitivity of 97.6% and specificity of 90% in detecting tumor recurrence. The positive predictive value, negative predictive value, and accuracy were 95.3%, 94.7%, and 95.1%, respectively. Locoregional disease was seen in 16 (37.2%) PET/CT studies, distant metastases were seen in 13 (30.2%), and 14 (32.5%) studies showed both locoregional disease and metastasis. When comparable CI was available, PET/CT showed a better specificity than CI for detection of recurrence.

CONCLUSIONS

Integrated FDG PET/CT can detect recurrence in GBC with high sensitivity and specificity. Routine use of PET/CT in these patients will detect recurrence early and change the subsequent management.

Risk stratification of gallbladder polyps (1-2 cm) for surgical intervention with 18F-FDG PET/CT

We assessed the value of (18)F-FDG uptake in the gallbladder polyp (GP) in risk stratification for surgical intervention and the optimal cutoff level of the parameters derived from GP (18)F-FDG uptake for differentiating malignant from benign etiologies in a select, homogeneous group of patients with 1- to 2-cm GPs.

METHODS

Fifty patients with 1- to 2-cm GPs incidentally found on the CT portion of PET/CT were retrospectively analyzed. All patients had histologic diagnoses. GP (18)F-FDG activity was visually scored positive (≥liver) or negative (<liver). Maximal standardized uptake value of the GP (SUVgp) and ratio of SUVgp to mean SUV of the liver (GP/L ratio) were also measured. Univariate and multivariate logistic regression analyses were performed to determine the utility of patient and clinical variables--that is, sex, age, gallstone, polyp size, and three (18)F-FDG-related parameters in risk stratification.

RESULTS

Twenty GPs were classified as malignant and 30 as benign. Multivariate analyses showed that the age and all parameters (visual criteria, SUVgp, and GP/L) related to (18)F-FDG uptake were significant risk factors, with the GP/L being the most significant. The sex, size of GPs, and presence of concurrent gallstones were found to be insignificant.

CONCLUSION

(18)F-FDG uptake in a GP is a strong risk factor that can be used to determine the necessity of surgical intervention more effectively than other known risk factors. However, all criteria derived from (18)F-FDG uptake presented in this series may be applicable to the assessment of 1- to 2-cm GPs.

Value of PET/CT in the management of primary hepatobiliary tumors, part 2

OBJECTIVE

Primary hepatobiliary malignancies consist of hepatocellular carcinoma, cholangiocarcinoma, and gallbladder cancer. Benign hepatic lesions include hepatic cysts, hemagiomas, adenomas, and focal nodular hyperplasias. The utility of PET/CT in imaging primary hepatobiliary lesions varies according to the type and location of the lesion.

CONCLUSION

There is a consistent benefit to the use of PET/CT for detection and staging, and it ultimately helps to establish the best course of treatment and to determine prognosis. In addition, PET/CT is very useful in local ablative and systemic therapy assessment and surveillance for hepatobiliary malignancies.

[Positron tomography with 18F-fluorodeoxyglucose in the preoperative evaluation of gall bladder lesions suspicious of malignancy. Diagnostic utility and clinical impact]

BACKGROUND

Gallbladder carcinoma is a neoplasm having a poor prognosis in which the role of the positron emission tomography with (18)F-fluordeoxyglucose as a diagnostic tool, although of possible usefulness, has not been well-defined.

METHODS/DESIGN

It is a prospective cohort of patients with radiologically malignant suspicious gallbladder lesions. A staging diagnostic presurgical FDG-PET study was carried out in each patient using both dedicated PET and multimodality PET-CT scanners. Diagnostic accuracy parameters were calculated from the results of PET imaging and were correlated with the condition and/or the clinical course of the patients. The clinical impact of its implementation in the diagnosis of gallbladder carcinoma was also analyzed.

RESULTS

A total of 42 patients were recruited (22 malignant lesions, 20 benign). Overall diagnostic accuracy was 83.33% for the diagnosis of the primary lesion, 88.89% for the evaluation of lymph node involvement and 85.1% for the evaluation of metastatic disease. Mean SUVmax in malignant gallbladder lesions was 6.14±2.89. ROC curve showed a cut-off value of 3.65 in the SUVmax for malignancy. Accuracy of PET studies alone (n=21) was slightly lower than that of the PET/CT (n=21). FDG-PET changed the management of 14.8% of the population due to the identification of unsuspected metastatic disease.

COMMENTS

FDG-PET accurately diagnoses malignancy or benignity of suspicious gallbladder lesions, with the addition of its capacity to identify unsuspected metastatic disease. PET-CT improves the diagnostic accuracy of the procedure, due to the metabolic-structural complementarity of their information. The SUVmax has a complementary value added to the visual analysis.

FDG-PET for hepatobiliary and pancreatic cancer: Advances and current limitations

In Japan, the use of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for some malignant tumors came to be covered by the National Health Insurance in 2002. In 2010, the health insurance coverage was expanded to all types of malignant tumors. However, since PET examination requires a large amount of capital investment, facilities at which PET is available are still limited. On the other hand, PET equipment has rapidly been introduced in large hospitals and in the diagnostic imaging centers of major cities during the past few years. Although numerous middle-sized and small hospitals cannot afford to perform PET, physicians can refer their patients to facilities where PET is available. Therefore, it is essential for general physicians to gain accurate knowledge on PET, including the appropriate indications for PET, in order to select patients for referral to PET facilities. PET is not always a useful tool, especially for lesions of the pancreas and hepatobiliary system, which is the main topic of this review. The indications of PET for lesions in these organs vary depending on the purpose of the examination. In this article, we review the indications for PET (or PET/computed tomography [CT]) using FDG of the liver, biliary tract, and pancreas.

Xanthogranulomatous cholecystitis complicated with primary sclerosing cholangitis: report of a case

Patients with primary sclerosing cholangitis (PSC) are at an increased risk for biliary tract carcinoma. The preoperative diagnosis of a biliary tract tumor as a malignancy is difficult, even using new modalities such as multidetector computed tomography (MD-CT), magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiography (ERC), and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET). Surgery is considered to be first line of treatment when these examinations suggest the presence of malignancy in the biliary tract, depending on both the curability of the cancer and the impaired liver function due to PSC. The management of gallbladder masses in patients with PSC remains problematic due to difficulties with the precise diagnosis and adequate surgery. Xanthogranulomatous cholecystitis (XGC) is a type of chronic cholecystitis, and sometimes coexists with gallbladder cancer. It is very difficult to make a preoperative diagnosis differentiating these two diseases. This report presents the case of a patient with XGC, who had been suspected of having gallbladder cancer before surgery, because the tumorous lesion emerged within a year and showed a focally increased uptake by FDG-PET during the follow up for PSC for years. This is the first case of XGC discovered during treatment for PSC.

Xanthogranulomatous cholecystitis mimicking gallbladder carcinoma with a false-positive result on fluorodeoxyglucose PET

Recently, several reports have demonstrated that fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is useful in differentiating between benign and malignant lesions in the gallbladder. However, there is a limitation in the ability of FDG-PET to differentiate between inflammatory and malignant lesions. We herein present a case of xanthogranulomatous cholecystitis misdiagnosed as gallbladder carcinoma by ultrasonography and computed tomography. FDG-PET also showed increased activity. In this case, FDG-PET findings resulted in a false-positive for the diagnosis of gallbladder carcinoma.

Xanthogranulomatous cholecystitis: the use of preoperative CT findings to differentiate it from gallbladder carcinoma

BACKGROUND AND AIM

A retrospective analysis was performed on 32 patients with histologically confirmed xanthogranulomatous cholecystitis (XGC) and 21 patients with gallbladder carcinoma who underwent surgical treatment between 1998 and 2007.

METHODS

All patients underwent preoperative CT scanning. The CT features analyzed were: the presence of intramural hypoattenuated nodules or bands, mucosal line, the patterns of wall thickening and enhancement, and the presence of stones in the gallbladder. The variables of the CT findings with XGC were analyzed using multivariate logistic regression analysis.

RESULTS

Intramural hypoattenuated nodules were observed in 21 patients (65%) with XGC, but in only six patients (29%) with gallbladder carcinoma (P < 0.01). The mucosal line was observed in 27 patients (84%) with XGC and in only four patients (19%) with gallbladder carcinoma (P < 0.0001). Gallstones were noted in 24 patients (75%) with XGC and five patients (24%) with gallbladder carcinoma (P < 0.001). There was no significant difference in the pattern of gallbladder wall thickening (diffuse or focal) and the presence of changes outside the gallbladder. Multivariate logistic regression analysis revealed from the CT features that the enhanced continuous mucosal line (P = 0.0013) and the presence of gallstones (P = 0.0072) were independently correlated with XGC.

CONCLUSION

CT features of the enhanced continuous mucosal line in a thickened gallbladder wall, together with gallstones in a patient with chronic gallbladder disease, are highly suggestive of XGC. Accurate diagnosis of XGC may therefore indicate the need to select a less aggressive surgical approach.

Does PET-CT scan have a role prior to radical re-resection for incidental gallbladder cancer?

BACKGROUND

Radical re-resection is offered to patients with non-metastatic, invasive, incidental gallbladder cancer. Data evaluating (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG PET-CT) in patients with incidental gallbladder cancer is sparse.

AIM

To evaluate the efficacy of integrated (18)F-FDG PET-CT in determining occult metastatic or residual local-regional disease in patients with incidental gallbladder cancer.

METHODS

Patients referred with incidental gallbladder cancer for radical re-resection were evaluated using multidetector computed tomography (MDCT) and PET-CT. Based on preoperative imaging, 24 out of 92 patients were found suitable for surgery. The two imaging modalities were evaluated with respect to residual and resectable disease.

RESULTS

In determining residual disease, MDCT had a sensitivity and positive predictive value (PPV) of 42.8%, each, while PET-CT had a sensitivity and PPV of 28.5 and 20%, respectively. In determining resectability, MDCT had a sensitivity, PPV, and accuracy of 100, 87.5, and 87.5%, respectively, as compared to PET-CT (sensitivity=100%, PPV=91.3%, accuracy=91.6%).

CONCLUSIONS

From our study, it appears that in patients with incidental gall bladder cancer without metastatic disease, PET-CT and MDCT seem to have roles complementing each other. PET-CT was able to detect occult metastatic or residual local-regional disease in some of these patients, and seems to be useful in the preoperative diagnostic algorithm of patients whose MDCT is normal or indicates locally advanced disease.

Gallbladder carcinoma update: multimodality imaging evaluation, staging, and treatment options

OBJECTIVE

The purpose of this article is to review the epidemiology, multimodality imaging findings, differential diagnosis, pathologic staging, and current treatment options of gallbladder carcinoma.

CONCLUSION

Understanding the characteristic appearances of primary gallbladder carcinoma at multiple imaging modalities can facilitate diagnosis and enable more accurate staging for triage to extended resection or an alternate therapy.

Port site and distant metastases of gallbladder cancer after laparoscopic cholecystectomy diagnosed by positron emission tomography

We report port site and distant metastases of unsuspected gallbladder cancer after laparoscopic cholecystectomy diagnosed by positron emission tomography (PET) in two patients. Patient 1, a 72-year-old woman was diagnosed as cholelithiasis and cholecystitis and received laparoscopic cholecystectomy. Unsuspected gallbladder cancer was discovered with histological result of well-differentiated squamous cell carcinoma of the gallbladder infiltrating the entire wall. A PET scan using F-18-fluorodeoxyglucose (FDG-PET) before radical resection revealed residual tumor in the gallbladder fossa and recurrence at port site and metastases in bilateral hilar lymph nodes. Patient 2, a 69-year-old woman underwent laparoscopic cholecystectomy more than one year ago with pathologically confirmed unsuspected adenosquamous carcinoma of stage pT1b. At 7-mo follow-up after surgery, the patient presented with nodules in the periumbilical incision. Excisional biopsy of the nodule revealed adenosquamous carcinoma. The patient was examined by FDG-PET, demonstrating increased FDG uptake in the right lobe of the liver and mediastinal lymph nodes consistent with metastatic disease. This report is followed by a discussion about the utility of FDG-PET in the gallbladder cancer.

Preoperative staging of biliary carcinoma using 18F-fluorodeoxyglucose PET: prospective comparison with PET+CT, MDCT and histopathology

The aim of this study was to evaluate the value of positron emission tomography with (18)F-labeled fluorodeoxyglucose (FDG-PET) as a preoperative diagnostic investigation in patients with biliary carcinoma. Seventy-two patients with potentially resectable biliary carcinoma underwent preoperative multidetector-row computed tomography (MDCT) and FDG-PET. Both diagnoses were compared with subsequent histopathology and follow-up results. In 64 lesions with biliary carcinoma, 57 (89%) revealed an intense focal accumulation on FDG-PET and were interpreted as malignant. On the other hand, eight benign lesions did not show any specific accumulation. Detection rate of FDG-PET in the nodular type of the tumour (96% or 27/28) was superior to that of the infiltrating type (74% or 17/23) (p = 0.037). For the evaluation of lymph node metastasis, the overall accuracy was 69% (35/51) in both FDG-PET and MDCT: FDG-PET had a lower sensitivity (33% vs. 57%) and a higher specificity (97% vs. 79%) than MDCT, although the values were not significantly different. FDG-PET revealed all six lesions of distant metastases in six patients including two lesions missed by MDCT. FDG-PET has high detectability of biliary malignancies. Like MDCT, FDG-PET offers only modest accuracy for regional lymph node staging, but it may reveal distant metastases missed by MDCT.