The risk of malignancy in ultrasound detected gallbladder polyps: A systematic review

Diagnostic performance of EUS-guided elastography for differential diagnosis of gallbladder polyp

BACKGROUND AND AIMS

It is difficult to differentiate between neoplastic and non-neoplastic gallbladder (GB) polyps before surgery. EUS-guided elastography (EUS-EG) is a noninvasive complementary diagnostic method. The utility of EUS-EG in the differential diagnosis of GB polyps has not been investigated. We investigated the diagnostic performance of EUS-EG for the differential diagnosis of GB polyps.

METHODS

Patients with GB polyps were prospectively enrolled from June 2020 until November 2022. EUS-EG and semiquantitative evaluation of the strain ratio (SR) were performed for differential diagnosis of GB polyps. Fifty-three eligible patients were divided into 2 groups based on the final diagnosis after surgery. Patient demographics, EUS characteristics, and SR values were compared. A receiver-operating characteristic curve analysis was performed to determine the optimal cutoff SR value that discriminates between neoplastic and non-neoplastic GB polyps.

RESULTS

The median SR value for neoplastic polyps (32.93 [interquartile range {IQR}, 22.37-69.02]) was significantly higher than for non-neoplastic polyps (5.40 [IQR, 2.36-14.44], P < .001). Significant differences were found in SR values between non-neoplastic, benign neoplastic (23.38 [IQR, 13.62-39.04]), and malignant polyps (49.25 [IQR, 27.90-82.00]). The optimal cutoff SR value to differentiate between neoplastic and non-neoplastic polyps was 18.4. In multivariable logistic regression, SR value >18.4 (odds ratio, 33.604; 95% confidence interval, 2.588-436.292) was an independent predictor of neoplastic polyps.

CONCLUSIONS

EUS-EG and SR values can be used as a supplementary method for evaluating GB polyps. (Clinical trial registration number: NCT04416763.).

Safety and Efficacy of Ultrasound-Guided Radiofrequency Ablation in the Treatment of Gallbladder Polyps

RATIONALE AND OBJECTIVES

To investigate the safety and efficacy of ultrasound-guided radiofrequency ablation (RFA) in the treatment of gallbladder polyps.

MATERIALS AND METHODS

A retrospective analysis was conducted on the medical records of 296 patients diagnosed with gallbladder polyps. The study observed the changes in lesions post-procedure within the ablation group, and compared whether there was a difference in the gallbladder contraction rate in patients before and after ablation. It also compared the liver function indicators before and after surgery, some indicators during the periprocedural period, and the incidence of complications in two groups of patients.

RESULTS

In the ablation group, all lesions (84/84) were completely ablated, and the absorption effect of the ablation lesions was good after the ablation. No significant differences were observed in the gallbladder contraction rate before ablation compared to 1 month and 3 months post-ablation (p > 0.05). After the operation, statistically significant differences were observed in ALT and TP between the two groups (all p < 0.05). Significant differences were observed between the two groups in terms of hospital stay, procedural time, postprocedural mobilization time, postprocedural exhaust time, postprocedural eating time, and VAS score on postprocedural day 3 (all p < 0.05). There was no significant difference in the incidence of complications between the two groups (x2=0.477，p = 0.490).

CONCLUSION

Our findings demonstrate that ultrasound-guided RFA is a safe, effective, and feasible treatment for gallbladder polyps, as it not only effectively eliminates the polyps but also preserves the physiological functions of the gallbladder.

Comparison of the Size Measurement of Gallbladder Polyps by Three Different Radiologists in Abdominal Ultrasonography

BACKGROUND

There is little information regarding the size measurement differences in gallbladder (GB) polyps performed by different radiologists on abdominal ultrasonography (US).

AIM

To reveal the differences in GB polyp size measurements performed by different radiologists on abdominal US.

METHODS

From June to September 2022, the maximum diameter of 228 GB polyps was measured twice on abdominal US by one of three radiologists (a third-year radiology resident [reader A], a radiologist with 7 years of experience in abdominal US [reader B], and an abdominal radiologist with 8 years of experience in abdominal US [reader C]). Intra-reader agreements for polyp size measurements were assessed by intraclass correlation coefficient (ICC). A Bland-Altman plot was used to visualize the differences between the first and second size measurements in each reader.

RESULTS

Reader A, reader B, and reader C evaluated 65, 77, and 86 polyps, respectively. The mean size of measured 228 GB polyps was 5.0 ± 1.9 mm. Except for the case where reader A showed moderate intra-reader agreement (0.726) for polyps with size ≤ 5 mm, all readers showed an overall high intra-reader reliability (reader A, ICC = 0.859; reader B, ICC = 0.947, reader C, ICC = 0.948), indicative of good and excellent intra-reader agreements. The 95% limit of agreement of reader A, B, and C was 1.9 mm of the mean in all three readers.

CONCLUSIONS

GB polyp size measurement on abdominal US showed good or excellent intra-reader agreements. However, size changes of approximately less than 1.9 mm should be interpreted carefully because these may be within the measurement error.

Practical approach to linear endoscopic ultrasound examination of the gallbladder

The gallbladder (GB) is a susceptible organ, prone to various pathologies that can be identified using different imaging techniques. Transabdominal ultrasound (TUS) is typically the initial diagnostic method due to its numerous well-established advantages. However, in cases of uncertainty or when a definitive diagnosis cannot be established, computed tomography (CT) or magnetic resonance imaging may be employed to provide more detailed information. Nevertheless, CT scans may sometimes offer inadequate spatial resolution, which can limit the differentiation of GB lesions, particularly when smaller yet clinically relevant abnormalities are involved. Conversely, endoscopic ultrasound (EUS) provides higher frequency compared to TUS, superior spatial resolution, and the option for contrast-enhanced harmonic imaging, enabling a more comprehensive examination. Thus, EUS can serve as a supplementary tool when conventional imaging methods are insufficient. This review will describe the standard EUS examination of the GB, focusing on its endosonographic characteristics in various GB pathologies.

Society of Radiologists in Ultrasound Consensus Conference Recommendations for Incidental Gallbladder Polyp Management: Interreader Agreement Among 10 Radiologists

BACKGROUND. The 2022 Society of Radiologists in Ultrasound (SRU) consensus conference recommendations for small gallbladder polyps support management that is less aggressive than earlier approaches and may help standardize evaluation of polyps by radiologists. OBJECTIVE. The purpose of the present study was to assess the interreader agreement of radiologists in applying SRU recommendations for management of incidental gallbladder polyps on ultrasound. METHODS. This retrospective study included 105 patients (75 women and 30 men; median age, 51 years) with a gallbladder polyp on ultrasound (without features highly suspicious for invasive or malignant tumor) who underwent cholecystectomy between January 1, 2003, and January 1, 2021. Ten abdominal radiologists independently reviewed ultrasound examinations and, using the SRU recommendations, assessed one polyp per patient to assign risk category (extremely low risk, low risk, or indeterminate risk) and make a possible recommendation for surgical consultation. Five radiologists were considered less experienced (< 5 years of experience), and five were considered more experienced (≥ 5 years of experience). Interreader agreement was evaluated. Polyps were classified pathologically as nonneoplastic or neoplastic. RESULTS. For risk category assignments, interreader agreement was substantial among all readers (k = 0.710), less-experienced readers (k = 0.705), and more-experienced readers (k = 0.692). For surgical consultation recommendations, inter-reader agreement was substantial among all readers (k = 0.795) and more-experienced readers (k = 0.740) and was almost perfect among less-experienced readers (k = 0.811). Of 10 readers, a median of 5.0 (IQR, 2.0-8.0), 4.0 (IQR, 2.0-7.0), and 0.0 (IQR, 0.0-0.0) readers classified polyps as extremely low risk, low risk, and indeterminate risk, respectively. Across readers, the percentage of polyps classified as extremely low risk ranged from 32% to 72%; as low risk, from 24% to 65%; and as indeterminate risk, from 0% to 8%. Of 10 readers, a median of zero change to 0 (IQR, 0.0-1.0) readers recommended surgical consultation; the percentage of polyps receiving a recommendation for surgical consultation ranged from 4% to 22%. Of a total of 105 polyps, 102 were nonneo-plastic and three were neoplastic (all benign). Based on readers' most common assessments for nonneoplastic polyps, the risk category was extremely low risk for 53 polyps, low risk for 48 polyps, and indeterminate risk for one polyp; surgical consultation was recommended for 16 polyps. CONCLUSION. Ten abdominal radiologists showed substantial agreement for polyp risk categorizations and surgical consultation recommendations, although areas of reader variability were identified. CLINICAL IMPACT. The findings support the overall reproducibility of the SRU recommendations, while indicating opportunity for improvement.

Preoperative prediction model for non-neoplastic and benign neoplastic polyps of the gallbladder

BACKGROUND

Gallbladder adenoma represents a precancerous lesion of gallbladder cancer. However, distinguishing it from cholesteryl polyps of the gallbladder before surgery is challenging. Thus, we aimed to comprehensively explore various risk factors contributing to the formation of gallbladder adenoma to facilitate an informed diagnosis and treatment by clinicians.

METHODS

We conducted a retrospective analysis of patients who had undergone cholecystectomy at the Affiliated Hospital of Qingdao University between January 2015 and December 2022. Following postoperative pathological examination, patients were categorized into cholesterol polyp and adenoma groups. We analyzed their baseline characteristics, ultrasound imaging variables, and biochemical data using logistic, lasso, and stepwise regression. Subsequently, we constructed a preoperative prediction model based on the independent risk factors.

RESULTS

Regression analysis of 520 gallbladder polyps and 288 gallbladder adenomas in the model group revealed that age, gallbladder wall thickness, polyp size, echogenicity, pedunculation, and adenosine deaminase (ADA) levels were independent predictors of gallbladder adenoma, all with P < 0.05. Using these indicators, we established a regression equation: Logistic (P) = -5.615 + 0.018 ∗ age - 4.64 ∗ gallbladder wall thickness + 1.811 ∗ polyp size + 2.855 ∗ polyp echo + 0.97∗ pedunculation + 0.092 ∗ ADA. The resulting area under the curve (AUC) value was 0.894 (95 % CI: 0.872-0.917, P < 0.01), with a sensitivity of 89.20 %, specificity of 79.40 %, and overall accuracy of 84.41 % for adenoma detection.

CONCLUSION

Age, polyp size, gallbladder wall thickness, polyp echogenicity, pedunculation, and ADA levels emerge as independent risk factors for gallbladder adenoma.

Risk stratification model for incidentally detected gallbladder polyps: A multicentre study

PURPOSE

We aimed to develop a 4-level risk stratification model using a scoring system based on conventional ultrasound to improve the diagnosis of gallbladder polyp.

METHOD

Patients with histopathologically confirmed gallbladder polyps were consecutively recruited from three medical centres. Conventional ultrasound findings and clinical characteristics were acquired prior to cholecystectomy. Risk factors for neoplastic and malignant polyps were used to build a risk stratification system via interobserver agreement and multivariate logistic regression analysis. The model was retrospectively trained using 264 pre-surgical samples and prospectively validated using 106 pre-surgical samples. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) and malignant polyp rate.

RESULTS

In total, 370 patients (mean age, 51.68 ± 14.41 years, 156 men) were enrolled in this study. Size (≥12 mm), shape (oblate or round), single, vascularity, gallbladder stone or sludge were considered risk factors for neoplastic polyps. Size (≥14 mm), shape (oblate), single, disrupted gallbladder wall, and gallbladder stone or sludge were risk factors for malignant polyps (all p < 0.05). In the scoring system, the sensitivity, specificity, and AUC of score ≥ 9 in diagnosing neoplastic polyps were 0.766, 0.788, and 0.876 respectively; and the sensitivity, specificity, and AUC of score ≥ 15 in diagnosing malignant polyps were 0.844, 0.926, and 0.949 respectively. In our model, the malignancy rates at the four levels were 0 % (0/24), 1.28 % (2/156), 9.26 % (5/54), and 70.37 % (38/54), respectively.

CONCLUSIONS

The 4-level risk stratification model based on conventional ultrasound imaging showed excellent performance in classifying gallbladder polyps.

Risk stratification of gallbladder masses by machine learning-based ultrasound radiomics models: a prospective and multi-institutional study

OBJECTIVE

This study aimed to evaluate the diagnostic performance of machine learning (ML)-based ultrasound (US) radiomics models for risk stratification of gallbladder (GB) masses.

METHODS

We prospectively examined 640 pathologically confirmed GB masses obtained from 640 patients between August 2019 and October 2022 at four institutions. Radiomics features were extracted from grayscale US images and germane features were selected. Subsequently, 11 ML algorithms were separately used with the selected features to construct optimum US radiomics models for risk stratification of the GB masses. Furthermore, we compared the diagnostic performance of these models with the conventional US and contrast-enhanced US (CEUS) models.

RESULTS

The optimal XGBoost-based US radiomics model for discriminating neoplastic from non-neoplastic GB lesions showed higher diagnostic performance in terms of areas under the curves (AUCs) than the conventional US model (0.822-0.853 vs. 0.642-0.706, p < 0.05) and potentially decreased unnecessary cholecystectomy rate in a speculative comparison with performing cholecystectomy for lesions sized over 10 mm (2.7-13.8% vs. 53.6-64.9%, p < 0.05) in the validation and test sets. The AUCs of the XGBoost-based US radiomics model for discriminating carcinomas from benign GB lesions were higher than the conventional US model (0.904-0.979 vs. 0.706-0.766, p < 0.05). The XGBoost-US radiomics model performed better than the CEUS model in discriminating GB carcinomas (AUC: 0.995 vs. 0.902, p = 0.011).

CONCLUSIONS

The proposed ML-based US radiomics models possess the potential capacity for risk stratification of GB masses and may reduce the unnecessary cholecystectomy rate and use of CEUS.

CLINICAL RELEVANCE STATEMENT

The machine learning-based ultrasound radiomics models have potential for risk stratification of gallbladder masses and may potentially reduce unnecessary cholecystectomies.

KEY POINTS

• The XGBoost-based US radiomics models are useful for the risk stratification of GB masses. • The XGBoost-based US radiomics model is superior to the conventional US model for discriminating neoplastic from non-neoplastic GB lesions and may potentially decrease unnecessary cholecystectomy rate for lesions sized over 10 mm in comparison with the current consensus guideline. • The XGBoost-based US radiomics model could overmatch CEUS model in discriminating GB carcinomas from benign GB lesions.

The risk and predictors of gallbladder cancer in patients with gallbladder polyps: A retrospective cohort study with an insight into confounding by indication

BACKGROUND AND AIM

We aimed to determine the risk and predictors of gallbladder cancer in all individuals with gallbladder polyps (GP) including those who did not have cholecystectomy.

METHODS

The STROCSS guideline was followed to conduct a retrospective cohort study. All individuals with GP between 2010 and 2019 were followed up to determine the risk and predictors of gallbladder cancer. The primary outcomes were gallbladder cancer and gallbladder dysplasia, and the secondary outcomes included polyp growth rate and polyp disappearance rate. Binary logistic regression analysis and receiver operating characteristic curve analysis were conducted to evaluate the outcomes.

RESULTS

Analysis of 438 patients showed risk of gallbladder cancer was 0.7% in all polyps (0% in polyps < 10 mm; 5.9% in polyps ≥ 10 mm). The risk of gallbladder dysplasia or cancer was 1.1% in all polyps (0% in polyps < 10 mm; 10% in polyps ≥ 10 mm). The polyp size (P = 0.0001) was predictor of cancer; however, patient's age (P = 0.1085), number of polyps (P = 0.9983), symptomatic polyps (P = 0.3267), and change in size (P = 0.9012) were not. Size of 21 mm was cut-off for risk of cancer (area under the curve [AUC]: 0.995, P < 0.001) and 11.8 mm for risk of dysplasia or cancer (AUC: 0.986, P < 0.001). The mean polyp growth rate was 0.3 mm/year and polyp disappearance rate was 16%.

CONCLUSIONS

The GP size remains the only predictor of malignant changes regardless of patient's age, patient's symptoms and number of polyps. The polyp growth rate is unremarkable, and a significant proportion disappears during follow-up. We changed our follow-up protocol with reduced number of scans and early discharge policy.

Is ultrasonography accurate for the diagnosis of gallbladder polyps? A review of cholecystectomy specimens from patients diagnosed with gallbladder polyps over a 14-years period

INTRODUCTION

Incidence of gallbladder polyps is 0,3-12%. It is important to differentiate pseudopolyps (cholesterol polyps, adenomyomatosis, inflammatory polyps), which do not have the capacity to become malignant, from true polyps (adenomas and adenocarcinomas). The main risk factors for malignancy are >6-10 mm, growth, sessile morphology, Indian ethnicity and primary sclerosing cholangitis. Ultrasound is the gold standard for diagnosis. Most polyps diagnosed by ultrasound are pseudopolyps. The main objective of this study is to analyse whether ultrasound is accurate for diagnosing true polyps in patients undergoing surgery for this reason.

METHODS

Retrospective observational study with prospective data entry of patients undergoing elective cholecystectomy for gallbladder polyps from 2007 to 2021. Surgery was indicated in symptomatic patients and in those with risk factors. The study has been approved by the Clinical Research Ethics Committee of our hospital.

RESULTS

We included 124 patients in our study. An elective laparoscopic cholecystectomy was performed in all of them. The mean age was 55,4 years and 61% were women. Of all patients, 65% were symptomatic at diagnosis. Only 3 patients had true polyps (2,4%). All of them were tubular adenomas. The rest of patients were false positives (97,6%). The adenoma size was 11, 6 and 5 mm, respectively. The surgical indication was due to polyp size or due to associated biliary symptoms.

CONCLUSION

Ultrasonography is not accurate for the diagnosis of gallbladder polyps. Validation of other complementary tests for the diagnosis of gallbladder polyps in asymptomatic patients could be relevant to avoid unnecessary surgeries.

SIUMB recommendations on the use of ultrasound in neoplastic lesions of the gallbladder and extrahepatic biliary tract

Extrahepatic biliary tract and gallbladder neoplastic lesions are relatively rare and hence are often underrepresented in the general clinical recommendations for the routine use of ultrasound (US). Dictated by the necessity of updated summarized review of current literature to guide clinicians, this paper represents an updated position of the Italian Society of Ultrasound in Medicine and Biology (SIUMB) on the use of US and contrast-enhanced ultrasound (CEUS) in extrahepatic biliary tract and gallbladder neoplastic lesions such as extrahepatic cholangiocarcinoma, gallbladder adenocarcinoma, gallbladder adenomyomatosis, dense bile with polypoid-like appearance and gallbladder polyps.

Gallbladder polyps and adenomyomatosis

Incidental findings are commonly detected during examination of the gallbladder. Differentiating benign from malignant lesions is critical because of the poor prognosis associated with gallbladder malignancy. Therefore, it is important that radiologists and sonographers are aware of common incidental gallbladder findings, which undoubtedly will continue to increase with growing medical imaging use. Ultrasound is the primary imaging modality used to examine the gallbladder and biliary tree, but contrast-enhanced ultrasound and MRI are increasingly used. This review article focuses on two common incidental findings in the gallbladder; adenomyomatosis and gallbladder polyps. The imaging features of these conditions will be reviewed and compared between radiological modalities, and the pathology, epidemiology, natural history, and management will be discussed.

GALLBLADDER POLYPS: CORRELATION AND AGREEMENT BETWEEN ULTRASONOGRAPHIC AND HISTOPATHOLOGICAL FINDINGS IN A POPULATION WITH HIGH INCIDENCE OF GALLBLADDER CANCER

BACKGROUND

Gallbladder polyps are becoming a common finding in ultrasound. The management has to consider the potential risk of malignant lesions.

AIMS

The aim of this study was to analyze the ultrasound findings in patients undergoing cholecystectomy due to gallbladder polyps and compare them for histopathological findings (HPs).

METHODS

Patients with an ultrasonographic diagnosis of gallbladder polyp and who underwent cholecystectomy from 2007 to 2020 were included in the study.

RESULTS

A total of 447 patients were included, of whom 58% were women. The mean age was 45±12 years. The mean size of polyps in US was 7.9±3.6 mm. Notably, 9% of polyps were greater than 10 mm, and single polyps were significantly larger than the multiple ones (p=0.003). Histopathological findings confirmed the presence of polyps in 88.4%, with a mean size of 4.8±3.4 mm. In all, 16 cases were neoplastic polyps (4.1%), 4 of them being malignancies, and all were single and larger than 10 mm. We found a significant correlation between ultrasound and histopathological findings polyp size determination (r=0.44; p<0.001). The Bland-Altman analysis obtained an overestimation of the US size of 3.26 mm. The receiver operating characteristic (ROC) curve analysis between both measures obtained an area under the receiver operating characteristic curve (AUC) of 0.77 (95%CI 0.74-0.81). Ultrasound polyps size larger than 10 mm had an odds ratio (OR) of 8.147 (95%CI 2.56-23.40) for the presence of adenoma and malignancy, with a likelihood ratio of 2.78.

CONCLUSIONS

There is a positive correlation and appropriate diagnostic accuracy between ultrasound size of gallbladder polyps compared to histopathological records, with a trend to overestimate the size by about 3 mm. Neoplastic polyps are uncommon, and it correlates with size. Polyps larger than 10 mm were associated with adenoma and malignancy.

Incidental Findings of Gallbladder and Bile Ducts-Management Strategies: General Aspects, Gallbladder Polyps and Gallbladder Wall Thickening-A World Federation of Ultrasound in Medicine and Biology (WFUMB) Position Paper

The World Federation of Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings with a series of position papers to give advice on characterization and management. The biliary system (gallbladder and biliary tree) is the third most frequent site for incidental findings. This first part of the position paper on incidental findings of the biliary system is related to general aspects, gallbladder polyps and other incidental findings of the gallbladder wall. Available evidence on prevalence, diagnostic work-up, malignancy risk, follow-up and treatment is summarized with a special focus on ultrasound techniques. Multiparametric ultrasound features of gallbladder polyps and other incidentally detected gallbladder wall pathologies are described, and their inclusion in assessment of malignancy risk and decision- making on further management is suggested.

Cholecystectomy for asymptomatic gallstones: Markov decision tree analysis

Gallstones are a common public health problem, especially in developed countries. There are an increasing number of patients who are diagnosed with gallstones due to increasing awareness and liberal use of imaging, with 22.6%-80% of gallstone patients being asymptomatic at the time of diagnosis. Despite being asymptomatic, this group of patients are still at life-long risk of developing symptoms and complications such as acute cholangitis and acute biliary pancreatitis. Hence, while early prophylactic cholecystectomy may have some benefits in selected groups of patients, the current standard practice is to recommend cholecystectomy only after symptoms or complications occur. After reviewing the current evidence about the natural course of asymptomatic gallstones, complications of cholecystectomy, quality of life outcomes, and economic outcomes, we recommend that the option of cholecystectomy should be discussed with all asymptomatic gallstone patients. Disclosure of material information is essential for patients to make an informed choice for prophylactic cholecystectomy. It is for the patient to decide on watchful waiting or prophylactic cholecystectomy, and not for the medical community to make a blanket policy of watchful waiting for asymptomatic gallstone patients. For patients with high-risk profiles, it is clinically justifiable to advocate cholecystectomy to minimize the likelihood of morbidity due to complications.

A New Risk Scoring System to Predict Malignancy in Gallbladder Polyps: a Single-Center Study

OBJECTIVE

Ultrasonography (US) is the most commonly used radiological method in the diagnosis of gallbladder polyps (GBPs). Patients diagnosed with GBPs on US are operated on with risk factors that do not have a high level of evidence. Our aim in this study is to determine the sensitivity of US in diagnosis GBPs, to define risk factors for neoplastic (NP) polyps, and to develop the risk scoring system.

MATERIALS AND METHODS

Between July 2011 and July 2021, 173 patients who were found to have GBPs in the pathology specimens after cholecystectomy were included in the study. Patients were divided into two groups: nonneoplastic and NP groups.

RESULTS

GBPs in patients who underwent abdominal US for any reason was 4.5%. The sensitivity of US in the diagnosis of GBPs was 56.6%. Comparison between groups, age ≥50, presence of symptoms, polyp size >12.5mm, single polyp, concomitant gallstones, and gallbladder wall thickness ≥4mm were statistically in the NP group. A risk scoring system was developed using these values. If the risk score was <4, 0.6% of GBPs was NP polyps. If the risk score was ≥4, 63.2% of GBPs were NP polyps.

CONCLUSION

Our risk scoring system can prevent unnecessary choelcystectomy. Because the incidence of NP polyps in low-risk patients (risk score <4) is extremely rare.

Risk of developing gallbladder cancer in patients with gallbladder polyps detected on transabdominal ultrasound: a systematic review and meta-analysis

OBJECTIVE

To estimate the risk of malignancy in gallbladder polyps of incremental sizes detected during transabdominal ultrasound (TAUS).

METHODS

We searched databases including MEDLINE, Embase, and Cochrane Library for eligible studies recording the polyp size from which gallbladder malignancy developed, confirmed following cholecystectomy, or by subsequent follow-up. Primary outcome was the risk of gallbladder cancer in patients with polyps. Secondary outcome was the effect of polyp size as a prognostic factor for cancer. Risk of bias was assessed using the Quality in Prognostic Factor Studies (QUIPS) tool. Bayesian meta-analysis estimated the median cancer risk according to polyp size. This study is registered with PROSPERO (CRD42020223629).

RESULTS

82 studies published since 1990 reported primary data for 67,837 patients. 67,774 gallbladder polyps and 889 cancers were reported. The cumulative median cancer risk of a polyp measuring 10 mm or less was 0.60% (99% credible range 0.30-1.16%). Substantial heterogeneity existed between studies (I2 = 99.95%, 95% credible interval 99.86-99.98%). Risk of bias was generally high and overall confidence in evidence was low. 13 studies (15.6%) were graded with very low certainty, 56 studies (68.3%) with low certainty, and 13 studies (15.6%) with moderate certainty. In studies considered moderate quality, TAUS monitoring detected 4.6 cancers per 10,000 patients with polyps less than 10 mm.

CONCLUSION

Malignant risk in gallbladder polyps is low, particularly in polyps less than 10 mm, however the data are heterogenous and generally low quality. International guidelines, which have not previously modelled size data, should be informed by these findings.

ADVANCES IN KNOWLEDGE

This large systematic review and meta-analysis has shown that the mean cumulative risk of small gallbladder polyps is low, but heterogeneity and missing data in larger polyp sizes (>10 mm) means the risk is uncertain and may be higher than estimated.Studies considered to have better methodological quality suggest that previous estimates of risk are likely to be inflated.

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.

Risk factors for gallbladder polyps observed through second-look abdominal sonography in patients with fatty liver disease

FLD, older age group, and alcohol consumption are major risk factors of GBP formation in Taiwanese population. The presence of GBPs might be revealed in second-look examinations of abdominal sonographies.

Management of Incidentally Detected Gallbladder Polyps: Society of Radiologists in Ultrasound Consensus Conference Recommendations

Gallbladder polyps (also known as polypoid lesions of the gallbladder) are a common incidental finding. The vast majority of gallbladder polyps smaller than 10 mm are not true neoplastic polyps but are benign cholesterol polyps with no inherent risk of malignancy. In addition, recent studies have shown that the overall risk of gallbladder cancer is not increased in patients with small gallbladder polyps, calling into question the rationale for frequent and prolonged follow-up of these common lesions. In 2021, a Society of Radiologists in Ultrasound, or SRU, consensus conference was convened to provide recommendations for the management of incidentally detected gallbladder polyps at US. See also the editorial by Sidhu and Rafailidis in this issue.

Follow-up of gallbladder polyps in a high-risk population of gallbladder cancer: a cohort study and multivariate survival competing risk analysis

BACKGROUND

The risk of neoplasia in gallbladder polyps seems to be low, but the evidence from populations at high-risk of gallbladder cancer is limited. We aimed to estimate the risk and to identify the factors associated with neoplastic polyps in a high-risk Hispanic population.

METHODS

A retrospective cohort was recruited between January 2010 and December 2019 at a Chilean university center. Multivariate survival analyses were conducted. Fine-Gray models were fitted to account for competing risks. Covariate adjustment was conducted using propensity scores. The main outcome was the development of gallbladder adenomas or adenocarcinoma.

RESULTS

Overall, 748 patients were included, 59.6% underwent cholecystectomy. The median follow-up of patients not subjected to cholecystectomy was 54.7 months (12-128.6 months). Seventeen patients (2.27%) developed the outcome. After adjustment by age, sex, intralesional blood flow, lithiasis and gallbladder wall thickening, only polyp size (≥10 mm, adjusted-HR: 15.01, 95%CI: 5.4-48.2) and number of polyps (≥3 polyps, adjusted-HR: 0.11, 95%CI: 0.01-0.55) were associated with neoplasia.

CONCLUSION

In a Hispanic population at high-risk for gallbladder cancer, gallbladder polyps seem to have a low risk of neoplasia. Polyp size was the main risk factor, while having multiple polyps was associated with an underlying benign condition.

Gallbladder-preserving polypectomy for gallbladder polyp by embryonic-natural orifice transumbilical endoscopic surgery with a gastric endoscopy

Background and aims

Cholecystectomy is performed for most gallbladder polyps (GPs). However, cholecystectomy results concerning complications in some patients. For benign GPs, adoption of gallbladder-preserving surgery is worth to recommend. We describe our experiences performing gallbladder-preserving polypectomy for GPs by embryonic-natural orifice transumbilical endoscopic surgery (E-NOTES) with a gastric endoscopy.

Methods

This is a retrospective study of patients with GPs who underwent gallbladder-preserving polypectomy by E-NOTES with a gastric endoscopy from April 2018 to September 2019 in our hospital. The operative time, intraoperative hemorrhage, intraoperative and postoperative complications, gallbladder emptying function were obtained and analyzed.

Results

The procedure was performed successfully in all 12 patients with 5 cases of single polyp and 7 cases of multiple polyps. The range of GPs size was 2 mm to 15 mm. The mean operation time was (95.33 ± 23.08) minutes (55–135 min). There were no adverse events including heavy bleeding, mortality and conversion to open surgery during operation. All patients were discharged in 4–5 days after surgery without postoperative complications such as delayed bleeding, fever, peritonitis, intra-abdominal abscess and abdominal wall incisional hernia. All patients were followed up at 1, 3, 6, and 12 months postoperation who had almost no visible incision on the umbilical region, no recurrent GPs. The gallbladder emptying function decreased one month after surgery, and gradually improved 3, 6 and 12 months after surgery.

Conclusion

E-NOTES gallbladder-preserving polypectomy is a safe and effective option for patients with GPs and is close to scar-free surgery which can be performed in routine clinical practice.

Grayscale ultrasonography findings for characterization of gallbladder wall thickening in non-acute setting: a systematic review and meta-analysis

BACKGROUND

The accurate characterization of gallbladder wall thickening (GWT) into benign or malignant on ultrasound (US) is a significant challenge.

METHODS

We searched the MEDLINE and EMBASE databases for studies reporting two-dimensional grayscale US in benign and malignant GWT. The pooled prevalence was calculated using a generalized linear mixed method with a random-effects model. The pooled sensitivity and specificity were calculated using a bivariate random-effects model.

RESULTS

Of the 7309 studies screened by titles, 73 studies with 18,008 patients were included. The most common findings in xanthogranulomatous cholecystitis (XGC) were lack of wall disruption and intramural hypoechoic nodules while adenomyomatosis (ADM) was frequently associated with intramural cysts and intramural echogenic foci. Echogenic foci, lack of gallbladder wall disruption, and hypoechoic nodules had a sensitivity of 89%, 77%, and 66% and specificity of 86%, 51%, and 80%, respectively for the diagnosis of benign GWT. Focal thickening and indistinct liver interface had a sensitivity of 75% and 55% and specificity of 64% and 69%, respectively for the diagnosis of malignant GWT.

CONCLUSION

intramural features (echogenic foci, hypoechoic nodules), gallbladder wall disruption, and liver interface are useful US features for the characterization of GWT.

Management and follow-up of gallbladder polyps: updated joint guidelines between the ESGAR, EAES, EFISDS and ESGE

Abstract

Main recommendations

Primary investigation of polypoid lesions of the gallbladder should be with abdominal ultrasound. Routine use of other imaging modalities is not recommended presently, but further research is needed. In centres with appropriate expertise and resources, alternative imaging modalities (such as contrast-enhanced and endoscopic ultrasound) may be useful to aid decision-making in difficult cases. Strong recommendation, low–moderate quality evidence.

Cholecystectomy is recommended in patients with polypoid lesions of the gallbladder measuring 10 mm or more, providing the patient is fit for, and accepts, surgery. Multidisciplinary discussion may be employed to assess perceived individual risk of malignancy. Strong recommendation, low-quality evidence.

Cholecystectomy is suggested for patients with a polypoid lesion and symptoms potentially attributable to the gallbladder if no alternative cause for the patient’s symptoms is demonstrated and the patient is fit for, and accepts, surgery. The patient should be counselled regarding the benefit of cholecystectomy versus the risk of persistent symptoms. Strong recommendation, low-quality evidence.

If the patient has a 6–9 mm polypoid lesion of the gallbladder and one or more risk factors for malignancy, cholecystectomy is recommended if the patient is fit for, and accepts, surgery. These risk factors are as follows: age more than 60 years, history of primary sclerosing cholangitis (PSC), Asian ethnicity, sessile polypoid lesion (including focal gallbladder wall thickening > 4 mm). Strong recommendation, low–moderate quality evidence.

If the patient has either no risk factors for malignancy and a gallbladder polypoid lesion of 6–9 mm, or risk factors for malignancy and a gallbladder polypoid lesion 5 mm or less, follow-up ultrasound of the gallbladder is recommended at 6 months, 1 year and 2 years. Follow-up should be discontinued after 2 years in the absence of growth. Moderate strength recommendation, moderate-quality evidence.

If the patient has no risk factors for malignancy, and a gallbladder polypoid lesion of 5 mm or less, follow-up is not required. Strong recommendation, moderate-quality evidence.

If during follow-up the gallbladder polypoid lesion grows to 10 mm, then cholecystectomy is advised. If the polypoid lesion grows by 2 mm or more within the 2-year follow-up period, then the current size of the polypoid lesion should be considered along with patient risk factors. Multidisciplinary discussion may be employed to decide whether continuation of monitoring, or cholecystectomy, is necessary. Moderate strength recommendation, moderate-quality evidence.

If during follow-up the gallbladder polypoid lesion disappears, then monitoring can be discontinued. Strong recommendation, moderate-quality evidence.

Source and scope

These guidelines are an update of the 2017 recommendations developed between the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), European Association for Endoscopic Surgery and other Interventional Techniques (EAES), International Society of Digestive Surgery–European Federation (EFISDS) and European Society of Gastrointestinal Endoscopy (ESGE). A targeted literature search was performed to discover recent evidence concerning the management and follow-up of gallbladder polyps. The changes within these updated guidelines were formulated after consideration of the latest evidence by a group of international experts. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence.

Key Point

• These recommendations update the 2017 European guidelines regarding the management and follow-up of gallbladder polyps.

Is there a role for growth status in distinguishing gallbladder adenomas from cholesterol polyps? - A retrospective study based on 520 cholecystectomy patients

INTRODUCTION

Gallbladder adenomas have cancerous potential and occur in 4-8.9% of gallbladder polyps. The growth status (size progression and growth rate during follow-up) of polyps and their effectiveness for predicting adenomas are poorly defined. Herein, we compared adenomas and cholesterol polyps based on the growth status and evaluated the reported risk factors in predicting neoplasm.

METHODS

We enrolled 520 patients who underwent preoperative ultrasonic follow-up more than 6 months with post-cholecystectomy pathologically confirmed gallbladder polyps. The patients were classified into adenoma and cholesterol polyp groups. Growth status, clinical characteristics, laboratory data, ultrasonic findings were reviewed and compared between the groups.

RESULTS

Seventy-nine adenomas and 441 cholesterol polyps were analyzed. The mean diameter of adenomas (cholesterol polyps) was 7.24 ± 4.36 mm (6.23 ± 2.88 mm) in the initial and 12.06 ± 4.61 mm (10.05 ± 2.95 mm) in the preoperative examination. The median size progression (range) of polyps in the cholesterol polyps [3 (0, 22)] mm was smaller than that in adenomas [4 (0, 21)] mm (p = .075). The mean growth rate of adenomas (1.07 ± 1.33 mm/6 months) was slightly faster than in cholesterol polyps (0.83 ± 1.04 mm/6 months) (p = .338). The indicators significantly associated with adenomas were age >49.5 years, lack of gallbladder polyps/cholelithiasis family history, polyp size >11.5 mm and solitary polyp (p = .005, p = .027, p = .001, and p = .021, respectively).

CONCLUSION

Growth status was not a valuable modality to distinguishing gallbladder adenomas from cholesterol polyps. Risk factors such as age, polyp size, and solitary polyp were effective in predicting adenomas.

Surgical management of suspected gallbladder cancer: The role of intraoperative frozen section for diagnostic confirmation

BACKGROUND

Preoperative diagnosis for suspected gallbladder cancers is challenging, with a risk of overtreating benign disease, for example, xanthogranulomatous cholecystitis, with radical cholecystectomies. We retrospectively evaluated the surgeon's intraoperative assessment alone, and with the addition of intraoperative frozen sections, for suspected gallbladder cancers from a tertiary hepatobiliary multidisciplinary team (MDT).

METHODS

MDT patients with complex gallbladder disease were included. Collated data included demographics, MDT discussion, operative details, and patient outcomes.

RESULTS

A total of 454 patients with complex gallbladder disease were reviewed, 48 (10.6%) were offered radical surgery for suspected cancer. Twenty-five underwent frozen section that led to radical surgery in 6 (25%). All frozen sections were congruent with final histopathology but doubled the operating time (p < 0.0001). Both the surgeon's subjective and additional frozen section's objective assessment, allowed for de-escalation of unnecessary radical surgery, comparing favourably to a 13.0% cancer diagnosis among radical surgery historically.

CONCLUSIONS

The MDT process was highly sensitive in identifying gallbladder cancers but lacked specificity. The surgeon's intraoperative assessment is paramount in suspected cancers, and deescalated unnecessary radical surgery. Intraoperative frozen section was a safe and viable adjunct at a cost of resources and operative time.

The Role of EUS and EUS-FNA in Differentiating Benign and Malignant Gallbladder Lesions

Endoscopic ultrasonography (EUS) has greater spatial resolution than other diagnostic imaging modalities. In addition, if gallbladder lesions are found and gallbladder cancer is suspected, EUS is an indispensable modality, enabling detailed tests for invasion depth evaluation using the Doppler mode and ultrasound agents. Furthermore, for gallbladder lesions, EUS fine-needle aspiration (EUS-FNA) can be used to differentiate benign and malignant forms of conditions, such as xanthogranulomatous cholecystitis, and collect evidence before chemotherapy. EUS-FNA is also useful for highly precise and specific diagnoses. However, the prevention of bile leakage, an accidental symptom, is highly important. Advancements in next-generation sequencing (NGS) technologies facilitate the application of multiple parallel sequencing to EUS-FNA samples. Several biomarkers are expected to stratify treatment for gallbladder cancer; however, NGS can unveil potential predictive genomic biomarkers for the treatment response. It is believed that NGS may be feasible with samples obtained using EUS-FNA, further increasing the demand for EUS-FNA.

The Role of Fine Needle Aspiration Cytology in the Diagnosis of Gallbladder Cancer: A Systematic Review

Gallbladder cancer is the most common malignancy of the biliary tract. When diagnosed in an advanced stage it has a very poor prognosis. Therefore, early diagnosis and thorough assessment of a suspicious gallbladder polyp is essential to improve survival rate. The aim of this systematic review is to assess the role of fine needle aspiration cytology (FNAC) in the management of gallbladder cancer. For that purpose, a systematic review was carried out in the MEDLINE, EMBASE, Cochrane, Scopus and Google Scholar databases between 1 July 2004 and 22 April 2021. Six studies with 283 patients in total were included. Pooled sensitivity and specificity of FNAC were 0.85 and 0.94, respectively, while the area under the calculated summary receiver operating characteristic (SROC curve (AUC) was 0.98. No complications were reported. Based on the high diagnostic performance of FNAC in the assessment of gallbladder masses, we suggest that every suspicious mass should be evaluated further with FNAC to facilitate the most appropriate management.

Bilious mask: parasite masquerading as malignant gall bladder polyp

A 31-year-old woman, presenting with right upper quadrant pain, was suspected to have malignant gall bladder polyp based on MRI and CT scan findings. She underwent radical cholecystectomy with excision of bile duct and hepaticojejunostomy. Surprisingly, histology revealed parasitic remnants within the bile duct wall with no evidence of malignancy. A year later, this young woman suffers significant impairment of quality of life, perhaps an aftermath to the radicality of the surgery. Our case demonstrates a masquerade of 'malignant biliary polyp' by a parasite. This raises the need for extensive investigations such as endoscopic ultrasound guided biopsies, parasitic serology and positron emission tomography (PET) scans when patients present with probable malignant biliary lesions, even in difficult-to-access areas. A preoperative diagnosis might have averted an unnecessary major surgery in this young woman.

Establishment of a nomogram prediction model for long diameter 10-15 mm gallbladder polyps with malignant tendency

BACKGROUND

Surgical indications for the treatment of gallbladder polyps are controversial. Evaluation of gallbladder polyps with malignant tendency and indications for cholecystectomy in patients with long diameter polyps of 10 to 15 mm require further analysis and discussion. In this study, our objective was to re-evaluate indications for the surgical resection of gallbladder polyps and construct a nomogram model for the prediction of gallbladder polyps with malignant tendency.

METHODS

Clinicopathologic data of 2,272 patients who had undergone cholecystectomy for gallbladder polyps were collected from 11 medical centers in China. Risk factor analyses and nomogram prediction model for gallbladder polyps with malignant tendency were conducted.

RESULTS

Excluding 311 patients with cholelithiasis and 488 patients with long diameter polyps ≤5 and >15 mm, factors that differed significantly among patients with gallbladder polyps having a long diameter of 6 to 9 mm (885 cases) and 10 to 15 mm (588 cases) were polyp detection time, CEA and CA19-9 levels, number of polyps, fundus, echogenicity, gallbladder wall thickness and postoperative pathologic features (P < .05). Among 588 patients with gallbladder polyps with a long diameter of 10 of 15 mm, multivariate analysis indicated the following independent risk factors of gallbladder polyps with malignant tendency: single polyps (OR = 0.286/P < .001), polyps with broad base (OR = 2.644/P = .001), polyps with medium/low echogenicity (OR = 2.387/P = .003), and polyps with short diameter of 7 to 9 or 10 to 15 mm (OR = 3.820/P = .005; OR = 2.220/P = .048, respectively). The C-index of the nomogram model and internal validation were .778 and .768, respectively. In addition, a sample online calculator for the nomogram prediction model had been created (https://docliqi.shinyapps.io/dynnom/).

CONCLUSION

Indications for cholecystectomy in patients with gallbladder polyps with a long diameter of 10 to 15 mm should be assessed by combining the information on short diameter, number of polyps, fundus, and echogenicity. The nomogram model can be used to predict the risk for the development of gallbladder polyps with malignant tendency.

Current update on gallbladder carcinoma

Gallbladder (GB) carcinoma is a relatively rare malignancy and is associated with poor prognosis. Numerous risk factors have been associated with the development of GB carcinoma. GB carcinomas may present as mass lesions replacing the GB, focal or diffuse thickening of the GB wall, and intraluminal mass in the GB. Various benign conditions can mimic GB carcinoma. This article reviews the epidemiology, pathology, clinical findings, imaging features, and management of GB carcinomas.

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.

Accuracy of Ultrasound in Diagnosing Gallbladder Polyps at a Community Hospital

Background and Objectives:

Polyps are reported on 1–10% of routine transabdominal ultrasound studies of the gallbladder. Prior studies have reported poor sensitivity and specificity for this diagnostic modality at determining malignant potential of polyps. The aim of this study is to determine the incidence of gallbladder polyps documented on ultrasound at a community hospital, evaluate the congruency of ultrasound with final histopathology, and explore factors which may improve ultrasound accuracy at diagnosing true adenomatous polyps.

Methods:

We conducted a 5-year retrospective cohort study of patients undergoing cholecystectomy at Danbury Hospital between 2014 and 2019, identifying those with a pre-operative ultrasound mention of a “polyp” or “mass.” We assessed the congruency of ultrasound findings with pathology reports.

Results:

Of the 2,549 cholecystectomies performed, 1,944 (76%) had pre-operative ultrasounds. Of those, 98 (5.0%) reported a polyp, measuring an average of 8.1 mm (SD 7.1 mm). Three (3.1%) specimens were identified as adenomas on final histopathology; the majority were benign pathologies including cholesterol polyp (18), cholesterolosis (20), adenomyoma (4), adenomyomatosis (7), and chronic or acute cholecystitis (44). Interestingly, only 1 of the 3 adenomas measured > 10 mm on ultrasound, the accepted indication for surgical resection.

Conclusions:

The accuracy of transabdominal ultrasound in diagnosing true polyps is poor, with only 3% of polyps identified as adenomas based on pathology. Surgeons should use caution when making clinical decisions based on polyps identified on ultrasound, and more stringent diagnostic criteria are needed in order to decrease the false positive rate for diagnosis and screening.

Gallbladder polyps ultrasound: what the sonographer needs to know

Gallbladder polyps are protuberances of the gallbladder wall projecting into the lumen. They are usually incidentally found during abdominal sonography or diagnosed on histopathology of a surgery specimen, with an estimated prevalence of up to 9.5% of patients. Gallbladder polyps are not mobile and do not demonstrate posterior acoustic shadowing; they may be sessile or pedunculated. Gallbladder polyps may be divided into pseudopolyps and true polyps. Pseudopolyps are benign and include cholesterolosis, cholesterinic polyps, inflammatory polyps, and localised adenomyomatosis. True gallbladder polyps can be benign or malignant. Benign polyps are most commonly adenomas, while malignant polyps are adenocarcinomas and metastases. There are also rare types of benign and malignant true gallbladder polyps, including mesenchymal tumours and lymphomas. Ultrasound is the first-choice imaging method for the diagnosis of gallbladder polyps, representing an indispensable tool for ensuring appropriate management. It enables limitation of secondary level investigations and avoidance of unnecessary cholecystectomies.

Gallbladder Disorders: A Comprehensive Review

Gallbladder disorders encompass a wide breadth of diseases that vary in severity. We present a comprehensive review of literature for the clinical presentation, pathophysiology, diagnostic evaluation, and management of cholelithiasis-related disease, acute acalculous cholecystitis, functional gallbladder disorder, gallbladder polyps, gallbladder hydrops, porcelain gallbladder, and gallbladder cancer.

Imaging based flowchart for gallbladder polyp evaluation

BACKGROUND

Preoperative differentiation between neoplastic and nonneoplastic gallbladder polyps, and the subsequent indication for cholecystectomy remains a clinical dilemma. The current 1 cm size threshold for neoplasia is unspecific. The aim of this study was to improve diagnostic work-up for gallbladder polyps using sonographic and MRI characteristics of neoplastic and nonneoplastic polyps.

METHODS

A prospective, exploratory study including patients undergoing cholecystectomy for gallbladder polyp(s) was conducted. Patients underwent targeted transabdominal ultrasound (TAUS) and MRI. Outcomes were sensitivity and specificity for polyp diagnosis, and the radiological characteristics of neoplastic and nonneoplastic polyp types. Histopathology after cholecystectomy was used as reference standard.

RESULTS

Histopathology demonstrated gallbladder polyps in 20/27 patients (74%): 14 cholesterol polyps, three adenomyomatosis, two adenomas and one gastric heterotopia. Sensitivity of polyp identification were 72% (routine TAUS) and 86% (targeted TAUS and MRI). Both adenomas were identified as neoplastic on targeted TAUS and MRI. Sonographic presentation as multiple, pedunculated polyps, either heterogeneous or with hyperechoic foci, or as single polyps containing cysts were limited to nonneoplastic polyps. On MRI hyperintense polyps on T1-weighted image were cholesterol polyps. An adenoma with high-grade dysplasia showed foci of decreased ADC values. We propose a checklist for polyp evaluation by targeted TAUS and a flowchart for radiological work-up of gallbladder polyps.

CONCLUSIONS

The presented checklist and flowchart could aid diagnostic work-up for gallbladder polyps compared to current routine ultrasound, by elimination of nonneoplastic polyps and ultimately improve treatment decision for patients with gallbladder polyps.

Effect of metabolic syndrome components on the risk of malignancy in patients with gallbladder lesions

Background: Gallbladder lesions have become more common nowadays. But there is limited evidence-based guidance on surveillance of these patients for malignancy. Predicting malignancy could help clinicians better manage this condition and improve the prognosis. We evaluated the independent and joint effects of metabolic syndrome components on the risk of malignancy among patients with gallbladder lesions.

Methods: Using a multicenter database, consecutive patients with pathologically confirmed gallbladder lesions between 2012 and 2019 were identified. Univariate and multivariate logistic regression analyses were used to evaluate the effects of metabolic syndrome components (diabetes, hypertension, dyslipidemia and obesity) as additive or combined indicators for the risk of malignancy. Unadjusted and adjusted odds ratios were calculated.

Results: Of the 625 patients, 567 patients were identified with benign gallbladder lesions and 58 patients with gallbladder cancer (GBC). GBC group had less obesity but more dyslipidemia. Among all metabolic syndrome components, only dyslipidemia was significantly associated with GBC (odds ratio 2.674, 95% confidence interval 1.173-6.094). Dyslipidemia was an independent risk factor for malignancy (adjusted odds ratio 2.164, 95% confidence interval 1.165-4.021), regardless of whether the other risk factors and metabolic syndrome components were combined. Patients with decreased high-density lipoprotein had 3.035-fold higher risk of malignancy (adjusted odds ratio 3.035, 95% confidence interval 1.645-5.600).

Conclusions: Dyslipidemia is associated with a 2.674-fold increase in the risk of malignancy in patients with gallbladder lesions. Dyslipidemia is an independent risk factor for malignancy, regardless of the presence of the other risk factors and metabolic syndrome components.

Gallbladder Carcinoma and Its Differential Diagnosis at MRI: What Radiologists Should Know

Gallbladder carcinoma is the most common cancer of the biliary system. It is challenging to diagnose because patients are often asymptomatic or present with nonspecific symptoms that mimic common benign diseases. Surgical excision is the only curative therapy and is best accomplished at early non-locally advanced stages. Unfortunately, gallbladder cancer often manifests at late locally advanced stages, precluding cure. Early tumors are often incidentally detected at imaging or at cholecystectomy performed for another indication. Typical imaging features of localized disease include asymmetric gallbladder wall thickening, polyps larger than 1.0 cm, and a solid mass replacing the gallbladder lumen. Advanced tumors are often infiltrative and can be confusing at CT and MRI owing to their large size. Determination of the origin of the lesion is paramount to narrow the differential diagnosis but is often challenging. It is important to identify gallbladder cancer and distinguish it from other benign and malignant hepatobiliary processes. Since surgical resection is the only curative treatment option, radiologist understanding and interpretation of pathways of nodal and infiltrative tumor spread can direct surgery or preclude patients who may not benefit from surgery. While both CT and MRI are effective, MRI provides superior soft-tissue characterization of the gallbladder and biliary tree and is a useful imaging tool for diagnosis, staging, and evaluation of treatment response. ^©RSNA, 2020.

Overtreatment of Nonneoplastic Gallbladder Polyps due to Inadequate Routine Ultrasound Assessment

BACKGROUND

The primary aim was to assess the diagnostic accuracy of routine ultrasound assessment for gallbladder polyps. The secondary aim was to identify the characteristics that differentiate neoplastic polyps from nonneoplastic polyps.

METHODS

A total of 156 patients with histopathologically proven gallbladder polyps in 4 Dutch hospitals between 2003 and 2013 were included. Sensitivity and specificity of ultrasound for polyp size, number of polyps, and polyp type were assessed using histopathological findings as a reference standard. In addition, diagnostic accuracy of sonographic size ≥1 cm for neoplasia was assessed. Subgroup analysis for patients with polyps as primary indication for cholecystectomy was performed. The sonographic polyp characteristics on preoperative routine ultrasound were described.

RESULTS

Fifty-six percent of gallbladder polyps were preoperatively identified on ultrasound, of which 31% were neoplastic. Sensitivity and specificity of ultrasound to estimate polyp size were 93 and 43% (subgroup; 92 and 33%). Sensitivity and specificity of sonographic polyp size ≥1 cm for neoplasia were 86 and 32% (subgroup; 94 and 26%). No specific sonographic characteristics for neoplastic polyps could be established due to lack of reporting.

CONCLUSION

Routine ultrasound assessment of polyps is associated with overestimation of polyp size and low specificity of sonographic size ≥1 cm for neoplasia, which contributes to surgical overtreatment of nonneoplastic polyps.

Gallbladder cancer revisited: the evolving role of a radiologist

Gallbladder cancer is the most common malignancy of the biliary tract. It is also the most aggressive biliary tumor with the shortest median survival duration. Complete surgical resection, the only potentially curative treatment, can be accomplished only in those patients who are diagnosed at an early stage of the disease. Majority (90%) of the patients present at an advanced stage and the management involves a multidisciplinary approach. The role of imaging in gallbladder cancer cannot be overemphasized. Imaging is crucial not only in detecting, staging, and planning management but also in guiding radiological interventions. This article discusses the role of a radiologist in the diagnosis and management of gallbladder cancer.

The management of gallbladder polyps

Neoplastic gallbladder polyps (NGP) are rare; the prevalence in the overall population is less than 10%. NGP are associated with a risk of malignant degeneration and must be distinguished from other benign gallbladder polypoid lesions that occur more frequently. NGP are adenomas and the main risk associated with their management is to fail to detect their progression to gallbladder cancer, which is associated with a particular poor prognosis. The conclusions of the recent European recommendations have a low level of evidence, based essentially on retrospective small-volume studies. Abdominal sonography is the first line study for diagnosis and follow-up for NGP. To prevent the onset of gallbladder cancer, or treat malignant degeneration in its early phases, all NGP larger than 10mm, or symptomatic, or larger than 6mm with associated risk factors for cancer (age over 50, sessile polyp, Indian ethnicity, or patient with primary sclerosing cholangitis) are indications for cholecystectomy. Apart from these situations, simple sonographic surveillance is recommended for at least five years; if the NGP increases in size by more than 2mm in size, cholecystectomy is indicated. Laparoscopic cholecystectomy is possible but if the surgeon feels that the risk of intra-operative gallbladder perforation is high, conversion to laparotomy should be preferred to avoid potential intra-abdominal tumoral dissemination. When malignant NGP is suspected (size greater than 15mm, signs of locoregional extension on imaging), a comprehensive imaging workup should be performed to search for liver extension: in this setting, radical surgery should be considered.

Outcomes of Gallbladder Polyps and Their Association With Gallbladder Cancer in a 20-Year Cohort

IMPORTANCE

Gallbladder polyps (GP) are found in more than 4% of adult abdominal ultrasonographs. Their growth pattern and association with gallbladder cancer (GBC) are poorly defined.

OBJECTIVE

To determine the growth pattern of GPs and their association with GBC.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 622 227 adult members (ie, aged 18 years or older) of Kaiser Permanente Northern California, an integrated health care delivery system, enrolled between January 1, 1995, and December 31, 2014. The GBC cohort comprised a total of 365 adults with GBC and prior ultrasonography, and the GP cohort comprised 35 970 adults with GPs present on ultrasonography. Data analysis was performed from March 2016 to November 2019.

EXPOSURES

Gallbladder polyps (quantitative size, <6 mm, 6 to <10 mm, and ≥10 mm or qualitative size [ie, tiny, small, moderate, and large]).

MAIN OUTCOMES AND MEASURES

For the GBC cohort, proportion of patients with GBC with polyps identified on preceding ultrasonograph. For the GP cohort, rates of GBC among those with polyps according to size and rate of GP growth of at least 2 mm over time.

RESULTS

The GBC cohort comprised 365 individuals (267 [73.1%] women; 173 [47.4%] white patients; median [interquartile range] age, 71 [61-79] years). After excluding 14 patients who did not have evaluation of polyp size, the final GP cohort comprised 35 856 adults, with 18 645 (52.0%) women, a median (interquartile range) age 50 (40-60) years, and 15 573 (43.3%) white patients. Gallbladder polyps were found in 22 patients (6.0%) in the GBC cohort and in 35 870 of 622 227 adults (5.8%) who underwent abdominal ultrasonography. Of these, 19 (0.053%) were diagnosed with GBC, similar to those without GP (316 of 586 357 [0.054%]). The unadjusted GBC rate per 100 000 person-years was 11.3 (95% CI, 6.2-16.3) overall and increased with polyp size, from 1.3 (95% CI, 0-4.0) with initial size of less than 6 mm (n = 17 531) to 128.2 (95% CI, 39.4-217.0) with initial size of 10 mm or larger (n = 2055). In those observed for at least 1 year, the rate was 3.6 (95% CI, 0.7-6.5) per 100 000 person-years. In 6359 patients with evaluable follow-up, unadjusted cumulative probabilities of polyp growth of at least 2 mm at 10 years were 66.2% (95% CI, 62.3%-70.0%) in polyps initially less than 6 mm and 52.9% (95% CI, 47.1%-59.0%) in polyps initially 6 mm to less than 10 mm.

CONCLUSIONS AND RELEVANCE

In this study, GBC rates were low and similar among patients with and without GPs. Growth of 2 mm or more appeared to be part of GP natural history. The results call into question the strategy of proactively following GP to detect GBC.

Clinical relevance of gallbladder polyps; is cholecystectomy always necessary?

BACKGROUND

Gallbladder polyps are common incidental findings during abdominal ultrasonography. Cholecystectomy is recommended for polyps equal or greater than 10 mm on ultrasound due to their malignant potential. However, the majority of lesions appear to be pseudopolyps with no malignant potential. Our aim was to determine the correlation between ultrasonographic findings and histopathological findings after cholecystectomy for gallbladder polyps in two institutions.

METHOD

A retrospective analysis was performed at two Dutch institutions of patients who underwent cholecystectomy. All cholecystectomies for suspected gallbladder polyps between January 2010 and August 2017 were included. Ultrasonographic and histopathological reports were analyzed.

RESULTS

A total of 108 patients underwent cholecystectomy for gallbladder polyps. At abdominal ultrasound sixty-five patients (60.2%) were diagnosed with multiple gallbladder polyps. The mean diameter of the polyps was 11 mm. On pathological examination after cholecystectomy, only three specimens harbored true polyps. No anomalies were found in 48 (44%) patients and 51 (47%) had cholesterolosis.

CONCLUSION

The prevalence of true gallbladder polyps was much lower in this study than reported in literature. After cholecystectomy for gallbladder polyps diagnosed by ultrasound, 97% of patients had non-neoplastic or not identifiable lesions in the gallbladder. These findings question the usefulness of current guidelines for management of suspected gallbladder polyps.

Validation of the 8th Edition of the American Joint Committee on Cancer Staging System for Gallbladder Cancer and Implications for the Follow-up of Patients without Node Dissection

PURPOSE

The 8th edition of gallbladder cancer staging in the American Joint Committee on Cancer (AJCC) staging system changed the T and N categories.

MATERIALS AND METHODS

In order to validate the new staging system, a total of 348 surgically resected gallbladder cancers were grouped based on the 8th edition of the T and N categories and compared with patients' survival.

RESULTS

Significant differences were noted between T1b-T2a (p=0.003) and T2b-T3 (p < 0.001) tumors, but not between Tis-T1a, T1a-T1b, and T2a-T2b tumors. However, significant survival differences were observed both by the overall and pair-wise (T1-T2, T2-T3) comparisons (all, p < 0.001) without dividing T1/T2 subcategories. When cases with ≥ 6 examined lymph nodes were evaluated, significant survival differences were observed among the entire comparison (p < 0.001) and pair-wise comparisons of N0-N1 (p=0.001) and N1-N2 (p=0.039) lesions. When cases without nodal dissection (NX) were additionally compared, significant survival differences were observed between patients with N0-NX (p=0.001) and NX-N1 (p < 0.001) lesions.

CONCLUSION

The T category in the 8th edition of the AJCC staging system did not completely stratify the prognosis of patients with gallbladder cancer. Modification by eliminating T subcategories can better stratify the prognosis. In contrast, the N category clearly determines patients' survival with ≥ 6 examined lymph nodes. The survival time in patients of gallbladder cancers without nodal dissection is between N0 and N1 cases. Therefore, close postoperative followed up is recommended for those patients.

The accuracy of ultrasonography for diagnosis of gallbladder polyps

INTRODUCTION

Gallbladder polyps (GBPs) are gallbladder lesions which can progress to gallbladder malignancy. The incidence has been estimated as high as 12.1% of all cholecystectomy patients. Gallbladder malignancy typically presents late, and therefore carries a poor prognosis. By identifying potential GBPs early, it would be possible to treat polyps before they undergo malignant change. The current gold standard for GBP identification is with histological examination which is performed after cholecystectomy. This study sought to assess whether radiological imaging could reliably identify GBPs and therefore guide management.

METHODS

1000 consecutive patients already undergoing cholecystectomy were sampled from two UK hospitals. Patients who underwent ultrasonography and had histological analysis of their gallbladders were selected. Overall 905 patients were included in the study.

RESULTS

There were 12 histologically confirmed GBPs in the cohort (1.33%). US correctly detected 1 GBP, with a sensitivity of 8.3% (95% CI 0.2-38.5%) and specificity of 96.0% (95% CI 94.5-97.2%). The overall accuracy was 94.8 (95% CI 93.2-96.2%).

CONCLUSION

These data show that US is an ineffective tool for GBP identification. The lack of prior operator exposure, imprecise nature of US and possible obstruction of images from underlying gallstone disease delivered a high rate of false positives.

IMPLICATIONS FOR PRACTICE

Surgical or oncological decisions regarding GBPs should not be based upon US findings alone as this would lead to unnecessary interventions. MRI should be investigated as an alternative imaging modality for GBP identification, as its differentiation of soft tissues could guide surgical management.

Precursors to Cholangiocarcinoma

Cancers of the biliary tract include intra- and extrahepatic cholangiocarcinomas and gallbladder cancer. Biliary tract cancers are diseases with unfavorable prognoses. In recent years, several lesions have been described as precursors that precede biliary cancers. They include flat and microscopic lesions known as biliary intraepithelial neoplasia, macroscopic and tumor-forming intraductal papillary biliary neoplasia, intraductal tubular neoplasia, and mucinous cystic neoplasm of the bile duct. These conditions are rarely diagnosed, while their natural history and progression to cancer have yet to be adequately characterized. This review examines the epidemiology, pathology, molecular biology, diagnosis, and therapy of these various precursors. Further research is required if we are to better understand this evolving field and improve the prevention and early detection of bile duct cancer.