A new strategy to predict the neoplastic polyps of the gallbladder based on a scoring system using EUS

Value of Conventional Ultrasound-based Scoring System in Distinguishing Adenomatous Polyps From Cholesterol Polyps

BACKGROUND AND AIM

Ultrasound has increased the detection of gallbladder polyps, but it has limitations in evaluating the nature of gallbladder polyps, especially the maximum size of 1.0 to 1.5 cm. We assessed the value of ultrasound scoring system based on independent predictive parameters in distinguishing adenomatous polyps from cholesterol polyps with the maximum size of 1.0 to 1.5 cm.

MATERIALS AND METHODS

We enrolled 163 patients with gallbladder polyps (1.0 to 1.5 cm) who underwent ultrasonography and cholecystectomy. Ultrasound image characteristics were compared between cholesterol polyps and adenomatous polyps in the training cohort from April 2018 to January 2020. An ultrasound scoring system was constructed in the training cohort, and its diagnostic performance was evaluated in the validation cohort from February 2020 to February 2021.

RESULTS

Maximum size, height/width ratio, stone or sludge, vascularity, and hyperechoic spot were significantly different between cholesterol polyps and adenomatous polyps in the training cohort ( P <0.05). The independent predictive parameters for adenomatous polyps were lower height/width ratio, presence of vascularity and absence of hyperechoic spot. The total score was as follows: (height/width ratio, <0.9=4, ≥0.9=0) + (vascularity, present=3, absent=0) + (hyperechoic spot, absent=2, present=0). The sensitivity, specificity and accuracy of ultrasound scoring system ≥5 for diagnosis of adenomatous polyps in the validation cohort were 73.33%, 80.49%, and 78.57%, respectively.

CONCLUSIONS

The ultrasound scoring system aids in distinguishing adenomatous polyps from cholesterol polyps, and effectively decreasing unnecessary cholecystectomy.

The usefulness of endoscopic ultrasound in the diagnosis of gallbladder lesions

Gallbladder tumors are neoplastic lesions; however, it can be difficult to distinguish between benign and malignant gall bladder tumors before surgery, although endoscopic ultrasound (EUS) is useful for differentiation. Fundamental B mode EUS (FB-EUS) and contrast-enhanced harmonic EUS (CH-EUS) are reported to be useful for the diagnosis of gallbladder tumor because they allow evaluation of polypoid lesion and gallbladder wall thickening. Scoring systems based on FB-EUS imaging are available for the diagnosis of malignant gallbladder polypoid lesions. The characteristic findings of malignant gallbladder polypoid lesions on CH-EUS include the presence of irregular intratumoral vessels and perfusion defects. The characteristic findings of malignant gallbladder wall thickening on FB-EUS include wall thickening >12 mm, hypoechoic internal echogenicity, inhomogeneous internal echo pattern, and disrupted wall layer, whereas CH-EUS findings include hypovascular enhancement and inhomogeneous contrast distribution pattern. In addition, FB-EUS and CH-EUS are useful for evaluating the stage of gallbladder carcinoma because they allow the evaluation of the depth of invasion of the gallbladder wall. It is usually difficult to obtain pathological evidence from gallbladder tumors before surgery and chemotherapy, even though the histological diagnosis is necessary for determining treatment policy. EUS-guided fine needle aspiration (EUS-FNA) is useful for obtaining pathological samples from gallbladder tumors before surgery and chemotherapy. The accuracy rate of EUS-FNA for gallbladder tumor is as high as 90%, but complications such as bile leakage and needle track seeding can be a problem, although it was reported that contrast-enhanced harmonic imaging is useful for avoiding them.

Diagnostic performance of endoscopic ultrasound-artificial intelligence using deep learning analysis of gallbladder polypoid lesions

BACKGROUND AND AIM

Endoscopic ultrasound (EUS) is the most accurate diagnostic modality for polypoid lesions of the gallbladder (GB), but is limited by subjective interpretation. Deep learning-based artificial intelligence (AI) algorithms are under development. We evaluated the diagnostic performance of AI in differentiating polypoid lesions using EUS images.

METHODS

The diagnostic performance of the EUS-AI system with ResNet50 architecture was evaluated via three processes: training, internal validation, and testing using an AI development cohort of 1039 EUS images (836 GB polyps and 203 gallstones). The diagnostic performance was verified using an external validation cohort of 83 patients and compared with the performance of EUS endoscopists.

RESULTS

In the AI development cohort, we developed an EUS-AI algorithm and evaluated the diagnostic performance of the EUS-AI including sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. For the differential diagnosis of neoplastic and non-neoplastic GB polyps, these values for EUS-AI were 57.9%, 96.5%, 77.8%, 91.6%, and 89.8%, respectively. In the external validation cohort, we compared diagnostic performances between EUS-AI and endoscopists. For the differential diagnosis of neoplastic and non-neoplastic GB polyps, the sensitivity and specificity were 33.3% and 96.1% for EUS-AI; they were 74.2% and 44.9%, respectively, for the endoscopists. Besides, the accuracy of the EUS-AI was between the accuracies of mid-level (66.7%) and expert EUS endoscopists (77.5%).

CONCLUSIONS

This newly developed EUS-AI system showed favorable performance for the diagnosis of neoplastic GB polyps, with a performance comparable to that of EUS endoscopists.

The Role of Endoscopic Ultrasound in the Diagnosis of Gallbladder Lesions

Gallbladder (GB) diseases represent various lesions including gallstones, cholesterol polyps, adenomyomatosis, and GB carcinoma. This review aims to summarize the role of endoscopic ultrasound (EUS) in the diagnosis of GB lesions. EUS provides high-resolution images that can improve the diagnosis of GB polypoid lesions, GB wall thickness, and GB carcinoma staging. Contrast-enhancing agents may be useful for the differential diagnosis of GB lesions, but the evidence of their effectiveness is still limited. Thus, further studies are required in this area to establish its usefulness. EUS combined with fine-needle aspiration has played an increasing role in providing a histological diagnosis of GB tumors in addition to GB wall thickness.

Surveillance of Gallbladder Polyps: A Literature Review

Little has been documented in existing literature regarding incidentally found gallbladder (GB) polyps. These clinically asymptomatic lesions are mostly benign, with only 5% progressing to malignancy. GB cancer, although rare, presents as an end-stage incurable disease. According to the current guidelines, cholecystectomy is recommended for polyps >10 mm in size for a better outcome. Thus, it is essential to know the clinical picture, surveillance, and treatment of these polyps earlier in the course of the disease to avoid the advancement of polyps to malignancy. This paper discusses the signs and symptoms, surveillance, treatment, and prognosis of GB polyps.

How Can We Manage Gallbladder Lesions by Transabdominal Ultrasound?

The most important role of ultrasound (US) in the management of gallbladder (GB) lesions is to detect lesions earlier and differentiate them from GB carcinoma (GBC). To avoid overlooking lesions, postural changes and high-frequency transducers with magnified images should be employed. GB lesions are divided into polypoid lesions (GPLs) and wall thickening (GWT). For GPLs, classification into pedunculated and sessile types should be done first. This classification is useful not only for the differential diagnosis but also for the depth diagnosis, as pedunculated carcinomas are confined to the mucosa. Both rapid GB wall blood flow (GWBF) and the irregularity of color signal patterns on Doppler imaging, and heterogeneous enhancement in the venous phase on contrast-enhanced ultrasound (CEUS) suggest GBC. Since GWT occurs in various conditions, subdividing into diffuse and focal forms is important. Unlike diffuse GWT, focal GWT is specific for GB and has a higher incidence of GBC. The discontinuity and irregularity of the innermost hyperechoic layer and irregular or disrupted GB wall layer structure suggest GBC. Rapid GWBF is also useful for the diagnosis of wall-thickened type GBC and pancreaticobiliary maljunction. Detailed B-mode evaluation using high-frequency transducers, combined with Doppler imaging and CEUS, enables a more accurate diagnosis.

Common Bile Duct Polyp—Rare But Not So Rare Cause Of Obstructive Jaundice

Polyps are usually found in gastrointestinal tract as their primary site of occurrence. In contrast, polyps in common bile duct (CBD) are uncommon. Biliary polyps can manifest as obstructive jaundice, which is the usually a presentation of common bile duct stone or malignant tumor of bile duct and pancreas. In this case series, we present five patients who had clinical manifestations of obstructive jaundice. However, systematic diagnostic approach in these patients revealed presence of polyps in distal CBD. We have focused on diagnostic challenges encountered during the investigation of CBD polyps.

Scoring System to Predict pt2 in Gallbladder Cancer Based on Carcinoembryonic Antigen and Tumor Diameter

BACKGROUND AND AIMS

T2 gallbladder cancer requires lymph node dissection for curative resection, whereas simple cholecystectomy is adequate to treat T1 gallbladder cancer. Hence, this study aimed to develop an accurate scoring system to preoperatively predict pT2 in gallbladder cancer.

MATERIAL AND METHODS

We retrospectively assessed data from 57 patients with suspected gallbladder cancer who underwent curative resection between September 2003 and May 2017. Six with apparent invasion of adjacent organs on preoperative images were excluded. We evaluated preoperative computed tomography, magnetic resonance and endoscopic ultrasonographic images, blood biochemistry, and the maximum standard uptake value in fluorodeoxyglucose-positron emission tomography images. We analyzed whether correlations between preoperative findings and the depth of tumor invasion could predict pT2.

RESULTS

The pathological diagnosis was gallbladder cancer in 30 (58.8%) patients, of whom 21 (69.9%) had pT2 or worse. Multivariate analyses selected carcinoembryonic antigen and tumor diameter as independent predictors of pT2 or worse (odds ratios = 1.741 and 1.098, respectively; 95% confidence intervals = 1.004-3.020 and 1.008-1.197, respectively). A regression formula was created using carcinoembryonic antigen and tumor diameter to calculate pT2 predictive scores. The area under the receiver operating characteristics curve of the pT2 predictive score was 0.873.

CONCLUSION

We created a scoring system to predict pT2 in gallbladder cancer using carcinoembryonic antigen and tumor diameter. The present findings suggested that carcinoembryonic antigen is important for the preoperative evaluation of gallbladder cancer.

Diagnosis and Treatment of Gallbladder Polyps: Current Perspectives

INTRODUCTION

Gallbladder polyps (GBPs) are generally harmless, but the planning of diagnosis and treatment of the GBP is of clinical importance due to the high mortality risk of delays in the diagnosis of gallbladder carcinomas that show polypoid development.

MATERIALS AND METHODS

GBPs are usually incidentally detected during ultrasonographic (USG) examinations of the abdomen. The risk of carcinoma development from polypoid lesions in the literature is reported as 0-27%. There is no consensus about the management of the GBPs. Herein, we reviewed the contemporary data to update our knowledge about diagnosis and treatment of gallbladder polyps.

RESULTS

Polyps can be identified in five different groups, primarily as neoplastic and non-neoplastic. Cholesterol polyps account for 60% of all cases. The most common (25%) benign polypoid lesions after cholesterol polyps are adenomyomas.

CONCLUSION

Ultrasonography and endoscopic ultrasonography seems to be the most important tool in differential diagnosis and treatment. Ultrasonography should be repeated in every 3-12 months in cases that are thought to be risky. Nowadays, the most common treatment approach is to perform cholecystectomy in patients with polyps larger than 10 mm in diameter. Radical cholecystectomy and/or segmental liver resections should be planned in cases of malignancy.

HOW TO CITE THIS ARTICLE

Dilek ON, Karsu S, et al. Diagnosis and Treatment of Gallbladder Polyps: Current Perspectives. Euroasian J Hepatogastroenterol 2019;9(1):40-48.

Transabdominal ultrasound and endoscopic ultrasound for diagnosis of gallbladder polyps

BACKGROUND

Approximately 0.6% to 4% of cholecystectomies are performed because of gallbladder polyps. The decision to perform cholecystectomy is based on presence of gallbladder polyp(s) on transabdominal ultrasound (TAUS) or endoscopic ultrasound (EUS), or both. These polyps are currently considered for surgery if they grow more than 1 cm. However, non-neoplastic polyps (pseudo polyps) do not need surgery, even when they are larger than 1 cm. True polyps are neoplastic, either benign (adenomas) or (pre)malignant (dysplastic polyps/carcinomas). True polyps need surgery, especially if they are premalignant or malignant. There has been no systematic review and meta-analysis on the accuracy of TAUS and EUS in the diagnosis of gallbladder polyps, true gallbladder polyps, and (pre)malignant polyps.

OBJECTIVES

To summarise and compare the accuracy of transabdominal ultrasound (TAUS) and endoscopic ultrasound (EUS) for the detection of gallbladder polyps, for differentiating between true and pseudo gallbladder polyps, and for differentiating between dysplastic polyps/carcinomas and adenomas/pseudo polyps of the gallbladder in adults.

SEARCH METHODS

We searched the Cochrane Library, MEDLINE, Embase, Science Citation Index Expanded, and trial registrations (last date of search 09 July 2018). We had no restrictions regarding language, publication status, or prospective or retrospective nature of the studies.

SELECTION CRITERIA

Studies reporting on the diagnostic accuracy data (true positive, false positive, false negative and true negative) of the index test (TAUS or EUS or both) for detection of gallbladder polyps, differentiation between true and pseudo polyps, or differentiation between dysplastic polyps/carcinomas and adenomas/pseudo polyps. We only accepted histopathology after cholecystectomy as the reference standard, except for studies on diagnosis of gallbladder polyp. For the latter studies, we also accepted repeated imaging up to six months by TAUS or EUS as the reference standard.

DATA COLLECTION AND ANALYSIS

Two authors independently screened abstracts, selected studies for inclusion, and collected data from each study. The quality of the studies was evaluated using the QUADAS-2 tool. The bivariate random-effects model was used to obtain summary estimates of sensitivity and specificity, to compare diagnostic performance of the index tests, and to assess heterogeneity.

MAIN RESULTS

A total of 16 studies were included. All studies reported on TAUS and EUS as separate tests and not as a combination of tests. All studies were at high or unclear risk of bias, ten studies had high applicability concerns in participant selection (because of inappropriate participant exclusions) or reference standards (because of lack of follow-up for non-operated polyps), and three studies had unclear applicability concerns in participant selection (because of high prevalence of gallbladder polyps) or index tests (because of lack of details on ultrasound equipment and performance). A meta-analysis directly comparing results of TAUS and EUS in the same population could not be performed because only limited studies executed both tests in the same participants. Therefore, the results below were obtained only from indirect test comparisons. There was significant heterogeneity amongst all comparisons (target conditions) on TAUS and amongst studies on EUS for differentiating true and pseudo polyps.Detection of gallbladder polyps: Six studies (16,260 participants) used TAUS. We found no studies on EUS. The summary sensitivity and specificity of TAUS for the detection of gallbladder polyps was 0.84 (95% CI 0.59 to 0.95) and 0.96 (95% CI 0.92 to 0.98), respectively. In a cohort of 1000 people, with a 6.4% prevalence of gallbladder polyps, this would result in 37 overdiagnosed and seven missed gallbladder polyps.Differentiation between true polyp and pseudo gallbladder polyp: Six studies (1078 participants) used TAUS; the summary sensitivity was 0.68 (95% CI 0.44 to 0.85) and the summary specificity was 0.79 (95% CI 0.57 to 0.91). Three studies (209 participants) used EUS; the summary sensitivity was 0.85 (95% CI 0.46 to 0.97) and the summary specificity was 0.90 (95% CI 0.78 to 0.96). In a cohort of 1000 participants with gallbladder polyps, with 10% having true polyps, this would result in 189 overdiagnosed and 32 missed true polyps by TAUS, and 90 overdiagnosed and 15 missed true polyps by EUS. There was no evidence of a difference between the diagnostic accuracy of TAUS and EUS (relative sensitivity 1.06, P = 0.70, relative specificity 1.15, P = 0.12).Differentiation between dysplastic polyps/carcinomas and adenomas/pseudo polyps of the gallbladder: Four studies (1,009 participants) used TAUS; the summary sensitivity was 0.79 (95% CI 0.62 to 0.90) and the summary specificity was 0.89 (95% CI 0.68 to 0.97). Three studies (351 participants) used EUS; the summary sensitivity was 0.86 (95% CI 0.76 to 0.92) and the summary specificity was 0.92 (95% CI 0.85 to 0.95). In a cohort of 1000 participants with gallbladder polyps, with 5% having a dysplastic polyp/carcinoma, this would result in 105 overdiagnosed and 11 missed dysplastic polyps/carcinomas by TAUS and 76 overdiagnosed and seven missed dysplastic polyps/carcinomas by EUS. There was no evidence of a difference between the diagnostic accuracy of TAUS and EUS (log likelihood test P = 0.74).

AUTHORS' CONCLUSIONS

Although TAUS seems quite good at discriminating between gallbladder polyps and no polyps, it is less accurate in detecting whether the polyp is a true or pseudo polyp and dysplastic polyp/carcinoma or adenoma/pseudo polyp. In practice, this would lead to both unnecessary surgeries for pseudo polyps and missed cases of true polyps, dysplastic polyps, and carcinomas. There was insufficient evidence that EUS is better compared to TAUS in differentiating between true and pseudo polyps and between dysplastic polyps/carcinomas and adenomas/pseudo polyps. The conclusions are based on heterogeneous studies with unclear criteria for diagnosis of the target conditions and studies at high or unclear risk of bias. Therefore, results should be interpreted with caution. Further studies of high methodological quality, with clearly stated criteria for diagnosis of gallbladder polyps, true polyps, and dysplastic polyps/carcinomas are needed to accurately determine diagnostic accuracy of EUS and TAUS.

Predictive Model for Neoplastic Potential of Gallbladder Polyp

GOAL

To provide the statistical predictive model for neoplastic potential of gallbladder polyp (GBP).

BACKGROUND

Many studies have attempted to define the risk factors for neoplastic potential of GBP. It remains difficult to precisely adapt the reported risk factors for the decision of surgery. Estimating the probability for neoplastic potential of GBP using a combination of several risk factors before surgical resection would be useful in patient consultation.

STUDY

We collected data of patients confirmed as GBP through cholecystectomy at Samsung Medical Center between January 1997 and March 2015. Those with a definite evidence for malignancy, such as adjacent organ invasion, metastasis on preoperative imaging studies, polyp >15 mm, and absence of proper preoperative ultrasonographic imaging were excluded. A total of 1976 patients were enrolled. To make and validate the predictive model, we divided the cohort into the modeling group (n=979) and validation group (n=997). Clinical information, ultrasonographic findings, and blood tests were retrospectively analyzed.

RESULTS

Clinical factors of older age, single lesion, sessile shape, and polyp size showed statistical significance for neoplastic potential of GBP in the modeling group. A predictive model for neoplastic potential of GBP was constructed utilizing the statistical outcome of the modeling group. Statistical validation was performed with the validation group to determine the optimal clinical sensitivity and specificity of the predictive model. Optimal cut-off value for neoplastic probability was 7.4%.

CONCLUSIONS

The predictive model for neoplastic potential of GBP may support clinical decisions before cholecystectomy.

Contrast-enhanced harmonic endoscopic ultrasonography for differential diagnosis of localized gallbladder lesions

BACKGROUND AND AIM

Differential diagnosis of localized gallbladder lesions is challenging. The aim of the present study was to evaluate the utility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) for diagnosis of localized gallbladder lesions.

METHODS

One hundred and twenty-five patients with localized gallbladder lesions were evaluated by CH-EUS between March 2007 and February 2014. This was a single-center retrospective study. Utilities of fundamental B-mode EUS (FB-EUS) and CH-EUS in the differentiation of gallbladder lesions and sludge plug were initially compared. Thereafter, these two examinations were compared with respect to their accuracy in the diagnosis of malignant lesions. Five reviewers blinded to the clinicopathological results evaluated microcirculation patterns in the vascular and perfusion images.

RESULTS

In the differentiation between gallbladder lesions and sludge plug, FB-EUS had a sensitivity, specificity, and accuracy of 82%, 100%, and 95%, respectively, whereas CH-EUS had a sensitivity, specificity, and accuracy of 100%, 99%, and 99%, respectively. FB-EUS-based diagnosis of carcinomas based on tumor size and/or shape had a sensitivity, specificity, and accuracy of 61-87%, 71-88%, and 74-86%, respectively. Additional information regarding irregular vessel patterns in the vascular image and/or heterogeneous enhancement in the perfusion image on CH-EUS increased the sensitivity, specificity, and accuracy for the diagnosis of carcinomas to 90%, 98%, and 96%, respectively. There was a significant difference between FB-EUS and CH-EUS in terms of carcinoma diagnosis.

CONCLUSION

CH-EUS was useful for the evaluation of localized gallbladder lesions.

The efficacy of real-time colour Doppler flow imaging on endoscopic ultrasonography for differential diagnosis between neoplastic and non-neoplastic gallbladder polyps

OBJECTIVES

We evaluated the usefulness of real-time colour Doppler flow (CDF) endoscopic ultrasonography (EUS) for differentiating neoplastic gallbladder (GB) polyps from non-neoplastic polyps.

METHODS

Between August 2014 and December 2016, a total of 233 patients with GB polyps who underwent real-time CDF-EUS were consecutively enrolled in this prospective study. CDF imaging was subjectively categorized for each patient as: strong CDF pattern, weak CDF pattern and no CDF pattern.

RESULTS

Of the 233 patients, 115 underwent surgical resection. Of these, there were 90 cases of non-neoplastic GB polyps and 23 cases of neoplastic GB polyps. In a multivariate analysis, a strong CDF pattern was the most significant predictive factor for neoplastic polyps; sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 52.2 %, 79.4 %, 38.7 %, 86.9 % and 73.9 %, respectively. Solitary polyp and polyp size were associated with an increased risk of neoplasm.

CONCLUSIONS

The presence of a strong CDF pattern as well as solitary and larger polyps on EUS may be predictive of neoplastic GB polyps. As real-time CDF-EUS poses no danger to the patient and requires no additional equipment, it is likely to become a supplemental tool for the differential diagnosis of GB polyps.

KEY POINTS

• Differential diagnosis between neoplastic polyps and non-neoplastic polyps of GB is limited. • The use of real-time CDF-EUS was convenient, with high agreement between operators. • The real-time CDF-EUS is helpful in differential diagnosis of GB polyps.

Applications of contrast-enhanced harmonic endoscopic ultrasound on biliary, focal liver lesions and vascular diseases

Over the last decade, the clinical applications of contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) have increased steadily. The development of second-generation ultrasound contrast agents has allowed superior visualization of the microvasculature and tissue perfusion of the target lesion. This methodology has proven useful in the differential diagnosis of solid pancreatic masses and lymph nodes. In addition, the applicability of CH-EUS has expanded to nonpancreas structures such as biliary, focal liver lesions, and vascular disease. This article focuses primarily on the novel applications of CH-EUS in biliary tract and visceral vascular diseases.

Preoperative predictive factors for gallbladder cholesterol polyp diagnosed after laparoscopic cholecystectomy for polypoid lesions of gallbladder

BACKGROUNDS/AIMS

We investigated patients' clinical and radiological data to determine preoperative factors that predict cholesterol gallbladder (GB) polyps of large size, which can be helpful for decision on further diagnostic tools.

METHODS

In this study, we retrospectively analyzed 126 patients who underwent laparoscopic cholecystectomy for GB polyps >10 mm diagnosed preoperatively by abdominal ultrasonography between February 2002 and February 2016 in Department of Surgery, Sanggye Paik Hospital. Patients were divided into non-cholesterol polyps group and cholesterol polyps group, based on the postoperative pathologic diagnosis. Clinical and radiological data, such as gender, age, body weight, height, body mass index (BMI), laboratory findings, size, number and shape of the polypoid lesions, and presence of the concurrent GB stone were compared between the two groups.

RESULTS

Of the 126 cases, 73 had cholesterol polyps (57.9%) and 53 cases were non-cholesterol polyps (42.1%). The younger age (<48.5 years), size of polyp <13.25 mm and multiple polyps were independent predictive variables for cholesterol polyps, with odd ratios (OR) of 2.352 (p=0.045), 5.429 (p<0.001) and 0.472 (p<0.001), respectively.

CONCLUSIONS

Age, size and polyp number were used to predict cholesterol GB polyp among polypoid lesions of the gallbladder >10 mm. For cases in which these factors are not applicable, it is strongly recommended to evaluate further diagnostic tools, such as computed tomography, endoscopic ultrasonography and tumor markers.

The clinical impact of ultrasound contrast agents in EUS: a systematic review according to the levels of evidence

BACKGROUND AND AIMS

The use of contrast-harmonic EUS (CH-EUS) in routine clinical practice is increasing rapidly but is not yet standardized. We present the levels of evidence (LEs) found in the literature to put its clinical outcomes in the appropriate perspective.

METHODS

We conducted a systematic review of the available English-language articles. The LEs were stratified according to the Oxford Centre for Evidence-Based Medicine guidelines.

RESULTS

Overall, 210 articles were included and presented according to different pathologic conditions. For pancreatic solid neoplasms, the pooled sensitivity and specificity in the diagnosis of pancreatic carcinoma were very high (LE 1); quantitative analysis and guidance of FNA were reported as investigational research (LE 2-3). For pancreatic cystic lesions, the identification of neoplastic solid components as hyperenhanced lesions represented a promising application of CH-EUS (LE 2). For lymph nodes, CH-EUS increased the diagnostic yield of B-mode EUS for the detection of malignancy (LE 2). For submucosal tumors, CH-EUS seemed useful for differential diagnosis and risk stratification (LE 2-3). For other applications, differential diagnosis of gallbladder and vascular abnormalities by CH-EUS were reported (LE 2-3).

CONCLUSIONS

The LEs of CH-EUS in the literature have evolved from the initial descriptive studies to multicenter and prospective trials, and even meta-analyses. The differential diagnosis between benign and malignant lesions is the main field of application of CH-EUS. With regard to pancreatic solid neoplasms, the concomitant use of both CH-EUS and EUS-FNA may have additive value in increasing the overall accuracy by overcoming the false-negative results associated with each individual technique. Other applications are promising but still investigational.

The role of endoscopic ultrasound in the diagnosis of gallbladder diseases

Endoscopic ultrasound (EUS) has recently played an increasing role in the diagnosis of gallbladder diseases. This review aims to summarize the role of EUS in the diagnosis of gallbladder lesions. EUS provides high-resolution images that can improve the diagnosis of gallbladder polypoid lesions and microlithiasis, in addition to evaluating gallbladder thickness and staging of gallbladder carcinoma. Contrast-enhancing agents may be useful for the differential diagnosis of gallbladder lesions, but the evidence of their effectiveness is still limited and further studies are required in this area to establish its usefulness. Endoscopic ultrasound combined with fine needle aspiration has played an increasing role in providing histological diagnosis of gallbladder tumors in addition to gallbladder thickening.

The Expanding Role of Contrast-Enhanced Endoscopic Ultrasound in Pancreatobiliary Disease

Since its introduction into clinical practice in the 1980s, endoscopic ultrasound (EUS) has been described as a good imaging modality for the diagnosis of pancreatobiliary diseases. However, differential diagnosis of certain lesions based only on B-mode ultrasound images can be challenging. Clinical use of ultrasound contrast agents has expanded the utility of EUS from that of detection to characterization of pancreatobiliary lesions based on the enhancement features of contrast-enhanced EUS (CE-EUS). Current low mechanical index techniques for CE-EUS using second-generation contrast agents have a number of distinct advantages over conventional diagnostic modalities in evaluating pancreatobiliary lesions, including real-time assessment of perfusion pattern, availability, and the absence of exposure to radiation. This article describes the technical aspects of CE-EUS and reviews the expanding indications in pancreatobiliary diseases and further development of this technique.

Gallbladder Cancer in the 21st Century

Gallbladder cancer (GBC) is an uncommon disease in the majority of the world despite being the most common and aggressive malignancy of the biliary tree. Early diagnosis is essential for improved prognosis; however, indolent and nonspecific clinical presentations with a paucity of pathognomonic/predictive radiological features often preclude accurate identification of GBC at an early stage. As such, GBC remains a highly lethal disease, with only 10% of all patients presenting at a stage amenable to surgical resection. Among this select population, continued improvements in survival during the 21st century are attributable to aggressive radical surgery with improved surgical techniques. This paper reviews the current available literature of the 21st century on PubMed and Medline to provide a detailed summary of the epidemiology and risk factors, pathogenesis, clinical presentation, radiology, pathology, management, and prognosis of GBC.

Utility of contrast-enhanced harmonic EUS in the diagnosis of malignant gallbladder polyps (with videos)

BACKGROUND

The differential diagnosis between benign and malignant polyps of the gallbladder (GB) is often challenging.

OBJECTIVES

To evaluate whether contrast-enhanced harmonic EUS (CEH-EUS) might be an accurate method for discriminating malignant GB polyps from benign polyps.

DESIGN

Observational study.

SETTING

Tertiary care medical center.

PATIENTS

Ninety-three patients with GB polyps larger than 10 mm in diameter that were detected by conventional EUS underwent CEH-EUS for evaluation of microvasculature.

INTERVENTION

CEH-EUS was performed using a radial echoendoscope and the extended pure harmonic detection mode.

MAIN OUTCOME MEASUREMENTS

The abilities of conventional EUS and CEH-EUS to diagnose malignant polyp were compared. Two blinded reviewers classified the perfusion images into 3 categories: diffuse enhancement, perfusion defect, or nonenhancement. The vessel images were categorized as having a regular spotty vessel, an irregular vessel, or no vessels.

RESULTS

An irregular vessel pattern determined by CEH-EUS aided in the diagnosis of malignant polyps with a sensitivity and specificity of 90.3% and 96.6%, respectively. The presence of perfusion defects, determined by CEH-EUS, was calculated to diagnose malignant polyps with a sensitivity and specificity of 90.3% and 94.9%, respectively. Based on the definitely determined diagnosis, sensitivity and specificity for CEH-EUS were 93.5% and 93.2% versus 90.0% and 91.1% for conventional EUS. In 8 cases, management changed after CEH-EUS.

LIMITATIONS

A tertiary medical center with a limited number of patients.

CONCLUSIONS

The presence of irregular intratumoral vessels or perfusion defects seen on CEH-EUS may be sensitive and accurate predictors of malignant GB polyps. CEH-EUS offers slightly improved diagnostic accuracy compared with EUS.

The diagnostic accuracy of transabdominal ultrasonography needs to be considered when managing gallbladder polyps

BACKGROUND

Transabdominal ultrasonography (TAUS) is the most commonly used modality to diagnose gallbladder (GB) disease. GB polyps are reported in 1-5.6 % of TAUS studies. Histopathologic studies suggest that there is a relationship between GB polyps and GB cancer. Previous literature suggests GB polyps reported on TAUS do not correlate well with histological findings. There have been recent advances in TAUS technology. We hypothesize the recent advances in TAUS technology have improved the accuracy of TAUS for diagnosing GB polyps.

METHODS

Radiology and pathology databases at our tertiary care center were retrospectively searched between January 1, 2000, and December 31, 2010. Ultrasound reports that suggested a GB polyp was present on TAUS were correlated to histopathology in cases where a cholecystectomy was performed. The pathology reports where a GB polyp was found were correlated with preoperative TAUS reports.

RESULTS

There were 102,740 TAUS reports referring to the GB, of which 6,612 (6.4 %) contained search terms suggesting a GB polyp was present. There were 13,278 cholecystectomy pathology reports, of which 159 (1.2 %) included a diagnosis of GB polyp. TAUS detected only 50 % of the polyps identified on histopathology. The sensitivity and specificity of TAUS for diagnosing GB polyps were 50.0 and 98.3 %, respectively. The positive and negative predictive values were 10.5 and 99.8 %.

CONCLUSIONS

Despite improvement in TAUS technology, the accuracy for GB polyps remains poor. This needs to be considered when managing patients with TAUS-detected GB polyps. We recommend that the decision to operate on TAUS-detected GB polyps be largely based on symptoms, and following GB polyps with TAUS should be discouraged.

Early diagnosis of gallbladder carcinoma: an algorithm approach

Gall bladder carcinoma is the most common biliary tract cancer. Delayed presentation and early spread of tumor make it one of the lethal tumors with poor prognosis. Considering that simple cholecystectomy for T1 disease could offer a potential cure, it is increasingly needed to identify it at early stages. Identification of high-risk cases and offering prophylactic cholecystectomy can decrease the incidence of gallbladder carcinoma. With advances in diagnostic tools like contrast-enhanced endoscopic ultrasound, elastography, multidetctor CT, MRI, and PET scan, we can potentially diagnose gallbladder carcinoma at early stages. This paper reviews the various diagnostic modalities available and an algorithmic approach to early diagnosis of gallbladder carcinoma.

Diagnosis and management of gallbladder polyps

Gallbladder cancer is a rather uncommon disease, when it gives symptoms it has usually reached an incurable stage. Therefore, every attempt must be made to find the asymptomatic stages and look for premalignant gallbladder polyps. Even if gallbladder cancer is a rare disease, gallbladder polyps are common, only a few polyps develop to cancer. This makes gallbladder polyps another problem: which are the polyps that must be surgically removed, which shall be followed-up, or for how long? The author used the keyword “gallbladder polypsn” in PubMed and reviewed the scientific literatures published from January 2000 to December 2011. The present review article has summarized almost all respects of gallbladder polyp, including the risk factors, clinical diagnosis and management, and comments made from the author, in which clinical treatments are recommended. It is author's purpose that the 11-year-knowledge about gallbladder polyps summarized from all worlds’ literatures is enough to know how clinicians will handle the next patient with gallbladder polyp.

Clinical and radiologic preoperative predicting factors for GB cholesterol polyp

PURPOSE

To use the clinical and radiological data to differentiate non-cholesterol versus cholesterol gall bladder (GB) polyps, which can be useful in deciding the treatment of the patient.

METHODS

One hundred and eighty-seven patients underwent cholecystectomy for GB polyps of around 10 mm for 10 years, and were divided into two groups, cholesterol polyps (146 patients) and non-cholesterol polyps (41 patients) based on the postoperative pathological findings. Gender, age, body weight, height, body mass index (BMI), symptoms, laboratory findings, size, number of polyps, presence of GB stone and maximum diameter measured by preoperative ultrasonography (USG), computed tomography (CT), and pathological diameter were subjected to comparative analysis.

RESULTS

Patients diagnosed with cholesterol polyps were younger in age and had higher BMI, and the total cholesterol levels and white blood cell levels were higher, but were not statistically significant. It was notable to see that 28.6% of the cholesterol polyps were not found in the preoperative CT yet the percentage of the undetectable rate was significantly lower (8%) in the non-cholesterol polyp group. There was a discrepancy in maximum diameters between the two radiological methods in both groups but the discrepancy was significantly larger in the cholesterol polyp group.

CONCLUSION

The clinical signs that can be helpful to diagnose whether it is a cholesterol polyp or not are younger patients who have high BMI, polyps which are detectable only on the USG and large maximum diameters between the USG and CT. And if the discrepancy of the maximum diameter is lesser than 1mm the polyp may be considered as a non-cholesterol polyp.

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.

Clinical usefulness of endoscopic ultrasonography in the differential diagnosis of gallbladder wall thickening

BACKGROUND AND AIMS

The differential diagnosis of gallbladder (GB) cancer from inflammatory diseases in patients with a thickened GB wall is difficult, whereas the pre-operative diagnosis of GB cancer is critical for selecting the appropriate surgical modality. We evaluated the clinical usefulness of endoscopic ultrasonography (EUS) for the differential diagnosis of GB wall thickening.

METHODS

The medical records, post-operative pathology reports, and images of EUS for 134 patients with GB wall thickening (>3 mm) who underwent laparoscopic or open cholecystectomies at our institution between December 2006 and February 2010 were retrospectively reviewed.

RESULTS

Thirteen patients (9.7%) had neoplastic GB wall thickening (11 with adenocarcinomas and two with adenosquamous carcinomas) and the remaining 121 patients (90.3%) had non-neoplastic GB wall thickening (117 with inflammatory GB wall thickening and four with adenomyomatosis). The mean (± standard deviation [SD], mm) GB wall thickness was 6.5 ± 3.3 and 19.4 ± 7.7 for non-neoplastic and neoplastic GB wall thickening, respectively (P < 0.01). The EUS variables which had a statistically significant association with neoplastic GB wall thickening were GB wall thickening >10 mm, disruption of the normal two layers of the GB wall, hypoechoic internal echogenecity, and the absence of gallstones. Based on the multivariate analyses, GB wall thickening >10 mm and hypoechoic internal echogenecity were independent predictive factors for neoplastic GB wall thickening.

CONCLUSIONS

The diagnostic power of EUS for differentiating neoplastic and non-neoplastic GB wall thickening could be improved by the appropriate application of some EUS variables.

Pre-operative factors that can predict neoplastic polypoid lesions of the gallbladder

AIM: To investigate the preoperative factors that can predict neoplastic polypoid lesions of the gallbladder (PLGs) as well as malignant PLGs.

METHODS: A retrospective analysis was conducted on the 210 consecutively enrolled patients who underwent cholecystectomy due to a PLG larger than 10 mm, as was determined by preoperative trans-abdominal ultrasonography or endoscopic ultrasonography. We analyzed the medical, laboratory, radiologic data and the pathologic results.

RESULTS: In 210 cases, 146 had non-neoplastic polyps (69.5%) and 64 cases were neoplastic polyps (30.5%). An older age (≥ 65 years), the presence of diabetes mellitus (DM) and the size of polyp (≥ 15 mm) were revealed to be independent predictive variables for neoplastic polyps with odd ratios (OR) of 2.27 (P = 0.044), 2.64 (P = 0.021) and 4.94 (P < 0.01), respectively. Among the neoplastic PLGs, an older age (≥ 65 years), the presence of DM and polyp size (≥ 15 mm) were associated with malignancy with ORs of 4.97 (P = 0.005), 6.13 (P = 0.001) and 20.55 (P < 0.001), respectively.

CONCLUSION: Among patients with PLGs larger than 10 mm in size, higher risk groups such as elderly patients more than 65 years old, those with DM or a large polyp size (≥ 15 mm) should be managed by cholecystectomy.

Endoscopic ultrasonography in diseases of the gallbladder

In recent years, endoscopic ultrasonography (EUS) has emerged as an important tool for the diagnosis and management of pancreaticobiliary disease. The close proximity of the echoendoscope to the biliary system allows detailed imaging of the gallbladder and adjacent structures. EUS is useful for the detection of occult cholelithiasis and biliary sludge and in the evaluation of suspected choledocholithiasis. It can be used to classify and predict neoplasia in polypoid lesions of the gallbladder and also to diagnose and stage gallbladder carcinoma. This article reviews the use of EUS in these diseases of the gallbladder.

Diagnosis and management of gallbladder polyps

Gallbladder polyps are frequently encountered on cross-sectional imaging, often in asymptomatic patients. Most are benign and of little clinical importance. However, some polyps do have a malignant potential. This article discusses the clinical presentation, diagnosis, and natural history of gallbladder polyps and risk factors for malignant polyps and indications for cholecystectomy.

Differential diagnostic and staging accuracies of high resolution ultrasonography, endoscopic ultrasonography, and multidetector computed tomography for gallbladder polypoid lesions and gallbladder cancer

OBJECTIVE

The authors undertook to investigate the diagnostic performance of high-resolution ultrasound (HRUS), and to compare the differential diagnostic and staging accuracies of endoscopic ultrasonography (EUS), HRUS, and multidetector computed tomography for gallbladder (GB) polypoid lesions and GB cancer.

SUMMARY OF BACKGROUND DATA

Endoscopic ultrasonography was considered the most sensitive diagnostic modality for GB polypoid lesions. However, recent technical advancements in other image modalities including conventional sonography (US) allow the production of comparable images.

METHODS

A total of 170 patients, with a more than 1-cm sized polypoid GB lesion, and without evidence of definite local invasion to adjacent organs during primary screening, were consecutively enrolled in this prospective, blind, comparative study. After excluding 26 patients with inappropriate medical histories, 144 patients were finally enrolled. All patients underwent surgical resection. Clinical diagnoses were compared with histopathologic findings by diagnostic modality.

RESULTS

Of the 144 patients, there were 115 (79.8%) cases of benign GB polypoid lesions and 29 (20.2%) cases of GB cancers. Diagnostic sensitivities for malignancy were 90% for HRUS, 86% for EUS, and 72% for CT. When evaluating the abilities of these modalities to predict GB cancer depth of invasion, we excluded 2 unusual GB malignancies (melanoma and lymphoma), HRUS was found to have the highest diagnostic accuracy of 62.9%; EUS and CT had accuracies of 55.5% and 44.4%, respectively.

CONCLUSIONS

The diagnostic accuracies of HRUS and EUS for the differential diagnosis of GB polypoid lesions were comparable. In view of patient comfort and no requirement for sedation, we consider that HRUS is likely to become an important diagnostic modality for the differential diagnosis and staging of GB polypoid lesions and early GB cancer.

[Natural course and treatment strategy of gallbladder polyp]

The polypoid lesions of gallbladder have explosively increased with enhanced feasibility of transabdominal ultrasonography. Most of small polyps less than 10 mm are benign and remain static for a long period. In small polyps, three to six month intervaled ultrasonography is warranted in the initial follow-up, but the duration of follow-up period is not clarified. The polypoid lesions larger than 10 mm show a quite different feature. They showed a remarkable risk of malignancy (34-88%) and should be treated by surgery. Furthermore, age more than 50 years and combined gallstone are important factors predicting malignancy in polypoid lesions of gallbladder. In addition, other factors including solitary polyp and the presence of symptoms are considered as risk factors. Laparoscopic cholecystectomy is a golden standard therapy for these polyps unless the suspicion of malignancy is high. The gallbladder polyps remain a problem of concern to both doctors and patient with the worry of malignancy. Thus, the comprehensive understanding of natural coruse of gallbladder polyp and risk factors of malignancy should be kept in mind.

Endoscopic ultrasound in the evaluation of radiologic abnormalities of the liver and biliary tree

Gastroenterologists increasingly find themselves in the un-enviable position of having to choose the optimal radiographic test to visualize the biliary tree and the liver. This dilemma is compounded by the rapid evolution of the available technologies and their ever-increasing resolution capabilities. Endoscopic ultrasound (EUS) has shown itself to be equally capable of providing detailed imaging of the biliary tree and of surrounding structures; its potential for evaluating liver lesions is just now being realized. EUS-fine needle aspiration (FNA) may supplant some of the existing technologies as it offers a way to sample masses, strictures, lymph nodes, and now certain segments of the liver and periportal regions. This review takes an in-depth look at the role of EUS in evaluating bile duct dilatation, suspected choledocholithiasis, biliary strictures, and polyps and masses of the gallbladder. It also reviews the literature on the exciting and rapidly evolving role of EUS-FNA evaluation of occult, metastatic, and primary hepato-cellular malignancies, as well as periportal lesions. Technologies such as EUS elastography may completely obviate FNA of liver lesions.

Hypoechoic foci on EUS are simple and strong predictive factors for neoplastic gallbladder polyps

BACKGROUND

EUS is an accurate imaging modality for delineating gallbladder (GB) structures; however, its clinical use in differentiating neoplastic GB polyps from nonneoplastic polyps is limited. Thus, we sought to characterize neoplastic GB polyps by analyzing unique EUS features. Our analysis revealed variably shaped, relatively hypoechoic portions in the core of polyps compared with general background echogenicity.

OBJECTIVE

Our purpose was to make a differential diagnosis between neoplastic and nonneoplastic GB polyps of less than 20 mm by use of EUS variables, including hypoechoic foci.

DESIGN

Retrospective single-center study.

SETTING

University teaching hospital.

PATIENTS

Patients (n = 88) underwent preoperative EUS and cholecystectomy for GB polyps smaller than 20 mm.

RESULTS

Hypoechoic foci were found in 30 of 33 patients (91%) with neoplastic polyps and 6 of 55 (11%) with nonneoplastic polyps. In a multivariate analysis, hypoechoic foci were the only significant predictive factor for neoplastic polyps (odds ratio [OR] 55.4, 95% CI, 8.26-371, P < .001); the sensitivity and specificity were 90% and 89%, respectively. In addition, polyps >15 mm had an increased risk of malignancy (OR 21.7, 95% CI, 2.35-201, P = .007), as did those with hypoechoic foci (OR 10.9; 95% CI, 1.01-117, P = .049).

LIMITATIONS

Retrospective review of selected patients from a tertiary medical center.

CONCLUSIONS

The presence of hypoechoic foci on EUS is a strong predictive factor for neoplastic polyps. EUS may be useful in developing a treatment strategy for GB polyps.

Endoscopic ultrasonography does not differentiate neoplastic from non-neoplastic small gallbladder polyps

AIM: To assess the ability of endoscopic ultrasonography (EUS) to differentiate neoplastic from non-neoplastic polypoid lesions of the gallbladder (PLGs).

METHODS: The uses of EUS and transabdominal ultrasonography (US) were retrospectively analyzed in 94 surgical cases of gallbladder polyps less than 20 mm in diameter.

RESULTS: The prevalence of neoplastic lesions with a diameter of 5-10 mm was 17.2% (10/58); 11-15 mm, 15.4% (4/26), and 16-20 mm, 50% (5/10). The overall diagnostic accuracies of EUS and US for small PLGs were 80.9% and 63.9% (P < 0.05), respectively. EUS correctly distinguished 12 (63.2%) of 19 neoplastic PLGs but was less accurate for polyps less than 1.0 cm (4/10, 40%) than for polyps greater than 1.0 cm (8/9, 88.9%) (P = 0.02).

CONCLUSION: Although EUS was more accurate than US, its accuracy for differentiating neoplastic from non-neoplastic PLGs less than 1.0 cm was low. Thus, EUS alone is not sufficient for determining a treatment strategy for PLGs of less than 1.0 cm.

Comparison of surgically resected polypoid lesions of the gallbladder to their pre-operative ultrasound characteristics

BACKGROUND

Polypoid lesions of the gallbladder (PLG) have been a common finding on ultrasound examinations of the abdomen and are more prevalent since our use of equipment incorporating pulse shaping increased bandwidth, and enhanced phase use for image reconstruction began in 1996. Our study correlates the pre-operative ultrasonographic findings of these lesions to the surgically resected specimen with specific regard to identifying neoplastic polyps.

METHODS

A retrospective review was performed of 130 patients who had a pre-operative ultrasound of the gallbladder and subsequently underwent cholecystectomy between August 1996 and July 2007 at the Mayo Clinic Rochester.

RESULTS

Seventy-nine pseudopolyps (cholesterol polyps, inflammatory polyps, and adenomyomas) and 15 neoplastic polyps were identified on histopathologic analysis. However, 36 patients (27%) did not have a PLG upon histopathologic analysis. Thirty-one polyps had suspicious ultrasonographic characteristics for neoplastic changes. Twenty-nine were > or = 10 mm, 12 had vascularity, and one demonstrated invasion. Of these, there were 23 pseudopolyps and six true polyps with neoplastic changes on final pathology (four dysplastic adenomas and two adenocarcinomas). Three asymptomatic polyps < or = 10 mm (4%) in maximum diameter based on pre-operative ultrasound imaging (US) had neoplastic changes at pathology (two dysplastic adenomas and one adenocarcinoma). Several statistically significant risk factors were identified that increased the likelihood for malignancy in a PLG: history of primary sclerosing cholangitis (PSC), local invasion, vascularity, and > or = 6 mm maximum diameter based on pre-operative US. Of PLGs < or = 10 mm, 7.4% were neoplastic. Twenty-five patients were followed up with at least two serial ultrasound examinations. Of these, seven demonstrated polyp growth. None of these specimens demonstrated neoplastic changes. The positive predictive value (PPV) and negative predictive value (NPV) for ultrasound diagnosing neoplastic changes based on current criteria was 28.5% and 93.1%, respectively, with a false negative rate of 5.0%. Expanding the criteria to include cholecystectomy for PLGs > or = 6 mm changes the positive predictive value and negative predictive value to 18.5% and 100%, respectively, with a false negative rate of 0%.

CONCLUSION

Histopathologic analysis of polypoid lesions of the gallbladder continues to be the gold standard to identify malignancy. Ultrasound has been used extensively in the pre-operative management of these lesions, but modern ultrasound techniques are unable to differentiate between benign and malignant PLGs with any certainty. We recommend that strong consideration be given to surgical resection of PLGs > or = 6 mm based on pre-operative US due to the significant risk of neoplasm. Additionally, PLGs in all patients with PSC, any patient in whom diligent long-term follow-up cannot be completed, and lesions that demonstrate growth, vascularity, invasion, or are symptomatic require cholecystectomy.

Management strategies for gallbladder polyps: is it possible to predict malignant gallbladder polyps?

BACKGROUND/AIMS

Gallbladder (GB) polyps are commonly encountered in clinical practice, and are found more frequently as the number of medical screening examinations increases. The aim of this study was to determine optimal practice guideline for surgical treatment and follow-up of GB polyps.

METHODS

Data from healthy subjects of Seoul National University Hospital (SNUH) Health Care System of Gangnam Center were used to investigate the true prevalence of GB polyps. We also enrolled 689 patients with GB polyps diagnosed at SNUH from May 1(st), 1988 to April 30(th), 2006.

RESULTS

The GB polyp prevalence was 6.1% (7.1% in males and 4.8% in females). The median follow-up duration in the 689 study patients was 60 months, and 139 (20%) of them had polyps >/=10 mm in size. Twenty-five of the 180 patients who underwent cholecystectomy had adenocarcinomas. The chi(2) test was used to identify which of the following were risk factors of malignancy: age, sex, symptoms, size, rate of growth, multiplicity, accompanying stones, and shape. Age (>/=57 years), presence of symptoms, size (>/=10 mm), and shape (sessile) were found to be statistically significant risk factors by univariate analysis. However, multivariate analysis identified only age (>/=57 years) and size (>/=10 mm) as independent predictors of malignancy.

CONCLUSIONS

The present study shows that GB polyps >/=10 mm in size in patients aged >/=57 years are the independent factors predicting malignancy of the GB.

Gallbladder villous adenoma in a patient with acromegaly: A case report

Villous adenomas are benign epithelial lesions with malignant potential that can occur in any part of the gastrointestinal tract. We present a case of a middle age woman with acromegaly who was investigated for nonspecific gastrointestinal complaints. Ultrasonography and subsequent endosonography diagnosed a large (4.5 cm), hyperechoic, sessile polyp with numerous pedicles. An open cholecystectomy was performed and revealed a villous adenoma with several foci of carcinoma in situ. Detailed investigations showed no other tumors of the gastrointestinal tract. After five years of follow-up, the patient reports no complaints, and the results of laboratory testing and imaging studies are within the normal range.

Can endoscopic ultrasonography differentiate nonneoplastic from neoplastic gallbladder polyps?

The present study aimed to clarify the endoscopic ultrasonography (EUS) features of nonneoplastic (cholesterol polyps and adenomyomatosis) and neoplastic (adenoma and adenocarcinoma) gallbladder polyps and to evaluate the effectiveness and limitation of EUS in the differential diagnosis of these lesions. We retrospectively compared EUS images with histologic findings in 29 surgical cases with gallbladder polyps with a diameter of 10 to 20 mm. Those cases were indicated for surgery based on the findings of a sessile appearance, a solitary lesion, low echogenicity, and/or a lobulated surface. Six of 10 cholesterol polyps were atypically seen as partially or completely hypoechoic due to predominant proliferation of glandular epithelia. Nine of 10 cholesterol polyps demonstrated an aggregation of hyperechoic spots, which represented multiple granules of cholesterosis. All adenomyomatoses (n = 10) showed multiple microcysts, which corresponded to proliferated Rokitansky-Aschoff sinuses. However, three of nine neoplastic lesions (three adenomas and six adenocarcinomas) showed one of these signs due to concomitant cholesterosis (n = 2) or proliferated Rokitansky-Aschoff sinuses (n = 1). In conclusion, 69% (20/29) of gallbladder polyps larger than 10 mm that were preoperatively suspected of malignancy were nonneoplastic. An aggregation of hyperechoic spots and multiple microcysts are considered to be important predictive factors for cholesterol polyps and adenomyomatosis, respectively. However, we should caution that these findings can also occur in neoplastic polyps when they contain a concomitant nonneoplastic component (cholesterosis or proliferated Rokitansky-Aschoff sinuses).

Long-term Survival of Patients with Gallbladder Cancer Detected during or after Laparoscopic Cholecystectomy

Little evidence is available regarding long-term survival of patients with gallbladder cancer that is discovered at the time of laparoscopic cholecystectomy (LC). Therefore the present study was performed to evaluate long-term outcomes of this disease. Of 1546 patients who underwent LC for benign gallbladder disease between January 1992 and January 2002, 8 patients (0.5%) had cancers that were found during or after LC. The median follow-up period was 55 months (range: 36-142 months). The gallbladder was resected without perforation in all cases. During surgery there was a suspicion of malignancy in 6 of 8 cases. Frozen section analysis showed that 2 had TNM stage Tis tumors, 2 had T1a tumors, and 2 had T2 tumors. Two patients with T2 tumors were immediately converted to extended cholecystectomy. The final pathology revealed another 2 tumors, and demonstrated that 3 patients had Tis tumors, 3 had T1a tumors, and 2 had T2N0M0 tumors. None of the patients underwent additional surgery. All patients survived with no evidence of recurrence during the median follow-up of 55 months. In conclusion, before and during LC, we have not overlooked T2 or more advanced tumor, which requires additional procedures for curative resection. This might result in good survival. We consider that an intensive preoperative work-up and meticulous inspection of the opened gallbladder should be mandatory to detect gallbladder cancer in patients who undergo LC. At present, this is not routinely practiced.

Gallbladder Polyps

Most small gallbladder polyps are benign and do not change significantly over time. They are usually incidental findings on ultrasound. Therefore, these polyps should be checked periodically with routine percutaneous ultrasonography. In the asymptomatic patient, gallbladder polyps that are greater than 1 cm in diameter should be treated with cholecystectomy. The size of the polyp and the patient greater than 50 years are important risk factors for malignant potential. Patients who have biliary pain and small gallbladder polyps without gallstones present a difficult management decision for the clinician. If the physician is confident that the polyps are the source of the pain, patients should be referred for cholecystectomy. Endoscopic ultrasound and positron emission tomography may prove to be useful in assessing the malignant potential of large gallbladder polyps. Laparoscopic cholecystectomy is the treatment of choice for most gallbladder polyps. If a malignant polyp is suspected, patients should undergo an open cholecystectomy.

[The application of digestive endoscopic ultrasonography in the gallbladder pathology]

A WELL DEFINED PATHOLOGY: Bilary lithiasis and vesicular parietal abnormalities constitute the totality of the gallbladder pathology. The surgical experience and widely current use of digestive imaging, notably ultrasonography, have contributed to enlightening our knowledge of this pathology. POTENTIAL DIAGNOSTIC PROBLEMS: There is no particular problem in the diagnosis of gallbladder lithiasis and its treatment is currently codified. However the discovery of thickened gallbladder wall or polyps increases the fear of gallbladder cancer. A FUNDAMENTAL ROLE FOR ENDOSCOPIC ULTRASONOGRAPHY: Within the framework of screening for cancer, endoscopic ultrasonography, the performance of which in gallbladder pathology has rarely been studied, appears promising. Other than its role in the control of the extension of gallbladder cancers, it provides reliable characterisation of most of the polyps. Hence its place today is unavoidable in the therapeutic decision trees of such affections.

Role of endoscopic ultrasonography in diseases of the extrahepatic biliary system

Endoscopic ultrasonography (EUS) is one of the most recent advances in gastrointestinal endoscopy. Available EUS devices include echoendoscopes, such as radial scanning and linear array echoendoscopes, and catheter ultrasound probes. Endoscopic ultrasonography has various applications, such as staging of gastrointestinal malignancy, evaluation of submucosal tumors, and has grown to be an important modality in evaluating the pancreaticobiliary system. With regard to the biliary system, EUS is useful for the detection and staging of ampullary tumors, detection of microlithiasis and choledocholithiasis and evaluation of benign and malignant bile-duct strictures. Endoscopic ultrasonography may be used as an adjunct to transabdominal ultrasound for the detection and characterization of gallbladder polyps. In addition, EUS is helpful in the staging of gallbladder cancer as well as in diagnosing anomalous pancreaticobiliary junction with its associated pancreatobiliary diseases. The present paper reviews the current applications of EUS for imaging and intervention in diseases of the extrahepatic biliary system.

Preoperative diagnosis and staging of gallbladder carcinoma by EUS

BACKGROUND

EUS has recently been shown to be efficacious for the preoperative assessment of depth of invasion of gallbladder carcinoma. This study assessed the value of EUS for determining T stage (International Union Against Cancer).

METHODS

Preoperative EUS findings in 41 patients with gallbladder carcinoma were analyzed retrospectively. EUS images were classified according to the shape of the tumor and the adjacent gallbladder wall structure as follows: type A, pedunculated mass with preserved adjacent wall structures; type B, sessile and/or broad-based mass with a preserved outer hyperechoic layer of the gallbladder wall; type C, sessile and/or broad-based mass with a narrowed outer hyperechoic layer; type D, sessile and/or broad-based mass with a disrupted outer hyperechoic layer. EUS and histopathologic findings were compared, including the depth of invasion of the tumor in the resection specimen.

RESULTS

The 4 categories of EUS images of gallbladder carcinoma correlated with the histologic depth of invasion and T stage. Accuracies for the EUS classification as type A corresponding to pTis, type B to pT1, type C to pT2, and type D to pT3-4 were, respectively, 100%, 75.6%, 85.3%, and 92.7%.

CONCLUSIONS

Preoperative EUS imaging accurately depicts T stage of gallbladder carcinoma and allows for effective therapeutic decision making.

EUS changes diagnosis from pancreatic to gallbladder carcinoma

A patient was referred for endoscopic ultrasound (EUS) for preoperative staging of what was believed to be pancreatic cancer, based on minimal findings on computed tomography (CT) and highly elevated CA19-9. EUS imaged a normal pancreas, but a tumor mass was identified in the gallbladder, and proven to be adenocarcinoma using EUS-guided fine-needle aspiration (FNA). Open cholecystectomy was curative. CA19-9 is not a highly specific marker. EUS is emerging as a highly sensitive and specific test for pancreatic cancer. EUS can complement other imaging modalities, and reveal unsuspected pathologies, such as in the patient described in this report, with major clinical impact.

The role of ultrasound in biliary and pancreatic diseases

The possibilities and the limits of transabdominal ultrasonography (US) in the diagnosis of bilio-pancreatic diseases are reviewed here in the light of the last 10 years' research. US remains the method of choice for the diagnosis of gallstones and is generally accepted as an initial imaging technique in gallstone complications, such as acute cholecystitis. Moreover the method can be useful for the detection of the biliary complications after laparoscopic cholecystectomy and after liver transplantation. US is still considered the first diagnostic procedure when stones are suspected in the common bile duct. The use of color Doppler can provide a differential diagnosis of gallbladder cancer with respect to other benign inflammatory or polypoid lesions. Color Doppler US allows to detect vascular complications of acute pancreatitis such as pseudoaneurysms. US is still considered useful for the initial screening of the pancreatic cancer. However, for staging other imaging techniques must be employed. With US useful informations are obtained in the diagnosis of cystic tumors of the pancreas and of pancreatic metastases. US is generally of little use for the diagnosis of endocrine tumors.