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

Current considerations for the surgical management of gallbladder adenomas

Gallbladder adenomas are rare lesions (0.5%) associated with potential malignant transformation, particularly with gallbladder adenomas that are ≥ 1 cm in size. Early detection and management are crucial for preventing lethal carcinoma development. These polyps can often be distinguished from the more often nonneoplastic cholesterol pseudopolyps (5%-10%), which are benign. Ultrasonography is the first-line tool for initial diagnosis and follow-up when indicated. The question is whether cholecystectomy is always necessary for all adenomas. The management of gallbladder adenomas is determined according to the size of the tumor, the growth rate of the tumor, the patient’s symptoms and whether risk factors for malignancy are present. Adenomas ≥ 1 cm in size, an age > 50 years and a familial history of gallbladder carcinoma are indications for immediate laparoscopic cholecystectomy. Otherwise, ultrasound follow-up is indicated. For adenomas 6-9 mm in size, the absence of ≥ 2 mm growth at 6 months, one year, and two years, as well as an adenoma sized < 5 mm without existing risk factors indicates that no further surveillance is required. However, it would be preferable to individualize the management in doubtful cases. Novel interventional modalities for preserving the gallbladder need further evaluation, especially to determine the long-term outcomes.

Follow-up imaging and surgical costs associated with different guidelines for management of incidentally detected gallbladder polyps

RATIONALE AND OBJECTIVES

To compare follow-up imaging and surgical cost implications of the Society of Radiologists in Ultrasound (SRU) guidelines, 2017 and 2022 European (EUR) guidelines, 2020 Canadian Association of Radiologists (CAR) recommendations, and 2013 American College of Radiology (ACR) White Paper for managing incidentally detected gallbladder polyps.

MATERIALS AND METHODS

253 consecutive patients with gallbladder polyps identified on ultrasound were independently reviewed by three radiologists for polyp size and morphology. Electronic medical records were reviewed for patient demographics, cholecystectomy (if performed) pathological findings, or any subsequent diagnosis of gallbladder cancer. For each patient, the following were calculated for each of the 5 guidelines studied: 1) number of recommended follow-up ultrasounds based on initial presentation, 2) number of surgical consultations recommended based on initial presentation, 3) number of surgical consultations recommended based on growth, and 4) associated imaging and surgical costs. Interrater agreement was calculated.

RESULTS

The SRU 2022 guidelines suggested significantly fewer follow-up ultrasounds and surgical consultations, leading to a cost reduction of 96.5 % and 96.7 % compared to European 2022 and 2017, respectively; 86.5 % compared to CAR; and 86.2 % compared to ACR guidelines. With SRU Recommendations, the majority of gallbladder polyps would be classified as extremely low risk (68.4 %), 30.8 % low risk, and 0.8 % indeterminate risk. In our cohort, a single case of gallbladder cancer was identified (26 mm) which would be recommended for surgical consult by all guidelines.

CONCLUSION

The SRU 2022 guidelines can lead to significant savings for patients, health systems, and society, while reducing unnecessary medical interventions for managing incidentally detected gallbladder polyps.

Percutaneous cholecystostomy: an unusual route of dissemination of gallbladder carcinoma

A 78-year-old male with high-risk surgical presented severe acute cholecystitis and required cholecystostomy. The patient was referred later for assessment of the surgical treatment. A cholangio-MRI revealed a lesion on the gallbladder fundus with hepatic lesions suggestive of metastatic gallbladder carcinoma, which was confirmed in the histological analysis. The tumor progressed despite the chemotherapy through the cholecystostomy tract and developed peritoneal carcinomatosis. The patient did not respond to chemotherapy and he died 12 months later.

Management of incidentally detected gallbladder polyps: a review of clinical scenarios using the 2022 SRU gallbladder polyp consensus guidelines

Gallbladder (GB) polyps are a common incidental finding on sonography, but only a small fraction of polyps become GB cancer. The Society of Radiologists in Ultrasound (SRU) consensus committee recently performed an extensive literature review and published guidelines for GB polyp follow-up/management to provide clarity among the many heterogeneous recommendations that are available to clinicians. As these guidelines have become adopted into clinical practice, challenging clinical scenarios have arisen including GB polyps in primary sclerosing cholangitis (PSC), high risk geographic/genetic patient populations, shrinking polyps, pedunculated vs sessile polyps, thin vs thick stalked polyps, vascular polyps and multiple polyps. According to the SRU guidelines, clinicians should refer to gastroenterology guidelines when managing GB polyps in patients with known PSC. If patients at high geographic/genetic risk develop GB polyps, 'extremely low risk' polyps may be managed as 'low risk' and 10-14 mm 'extremely low risk' or '7-14 mm' low risk polyps that decrease in size by ≥ 4 mm require no follow-up. Thin-stalked or pedunculated polyps are 'extremely low risk' and thick-stalked pedunculated polyps are 'low risk'. Sessile polyps are 'low risk' but should receive immediate specialist referral if features suggestive of GB cancer are present. Neither polyp multiplicity nor vascularity impact risk of GB cancer and follow up should be based on morphology alone.

Advances in the management of gallbladder polyps: establishment of predictive models and the rise of gallbladder-preserving polypectomy procedures

Gallbladder polyps are a common biliary tract disease whose treatment options have yet to be fully established. The indication of "polyps ≥ 10 mm in diameter" for cholecystectomy increases the possibility of gallbladder excision due to benign polyps. Compared to enumeration of risk factors in clinical guidelines, predictive models based on statistical methods and artificial intelligence provide a more intuitive representation of the malignancy degree of gallbladder polyps. Minimally invasive gallbladder-preserving polypectomy procedures, as a combination of checking and therapeutic approaches that allow for eradication of lesions and preservation of a functional gallbladder at the same time, have been shown to maximize the benefits to patients with benign polyps. Despite the reported good outcomes of predictive models and gallbladder-preserving polypectomy procedures, the studies were associated with various limitations, including small sample sizes, insufficient data types, and unknown long-term efficacy, thereby enhancing the need for multicenter and large-scale clinical studies. In conclusion, the emergence of predictive models and minimally invasive gallbladder-preserving polypectomy procedures has signaled an ever increasing attention to the role of the gallbladder and clinical management of gallbladder polyps.

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.

Analysis of ultrasonographic images using a deep learning-based model as ancillary diagnostic tool for diagnosing gallbladder polyps

BACKGROUND

Accurately diagnosing gallbladder polyps (GBPs) is important to avoid misdiagnosis and overtreatment.

AIMS

To evaluate the efficacy of a deep learning model and the accuracy of a computer-aided diagnosis by physicians for diagnosing GBPs.

METHODS

This retrospective cohort study was conducted from January 2006 to September 2021, and 3,754 images from 263 patients were analyzed. The outcome of this study was the efficacy of the developed deep learning model in discriminating neoplastic GBPs (NGBPs) from non-NGBPs and to evaluate the accuracy of a computer-aided diagnosis with that made by physicians.

RESULTS

The efficacy of discriminating NGBPs from non- NGBPs using deep learning was 0.944 (accuracy, 0.858; sensitivity, 0.856; specificity, 0.861). The accuracy of an unassisted diagnosis of GBP was 0.634, and that of a computer-aided diagnosis was 0.785 (p<0.001). There were no significant differences in the accuracy of a computer-aided diagnosis between experienced (0.835) and inexperienced (0.772) physicians (p = 0.251). A computer-aided diagnosis significantly assisted inexperienced physicians (0.772 vs. 0.614; p < 0.001) but not experienced physicians.

CONCLUSIONS

Deep learning-based models discriminate NGBPs from non- NGBPs with excellent accuracy. As ancillary diagnostic tools, they may assist inexperienced physicians in improving their diagnostic accuracy.

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.

Endoscopic Management of Gallbladder Disease

PURPOSE OF REVIEW

Diseases of the gallbladder can be increasingly managed through endoscopic interventions, either serving as an alternative to or obviating the need for cholecystectomy. In this review, we aim to review the most recent data on endoscopic management of the most common gallbladder diseases.

RECENT FINDINGS

The development of lumen-opposing metal stents (LAMS) marked a major shift in gallbladder management, with transmural techniques now well studied for management of cholecystitis. Endoscopic ultrasound (EUS) is also a well-developed technique for gallbladder imaging, comparable or superior to transabdominal ultrasound. Novel techniques with LAMS for gallbladder lesion/polyp resection and treatment of non-cholecystitis gallbladder diseases mark important milestones in gallbladder preservation and increasingly less invasive management of diseases of the gallbladder. There are multiple interventional endoscopic techniques that can be used to manage common gallbladder diseases including cholecystitis, cholelithiasis, gallbladder lesions/polyps, and gallbladder cancer. Ongoing development of novel therapeutic techniques holds promise for additional minimally invasive techniques in the future.

Ultrasound Surveillance of Small, Incidentally Detected Gallbladder Polyps: Projected Benefits by Sex, Age, and Comorbidity Level

OBJECTIVE

Incidentally detected gallbladder polyps are commonly encountered when performing upper abdominal ultrasound. Our purpose was to estimate the life expectancy (LE) benefit of ultrasound-based gallbladder surveillance in patients with small (6-7 to <10 mm), incidentally detected gallbladder polyps, accounting for patient sex, age, and comorbidity level.

METHODS

We developed a decision-analytic Markov model to evaluate hypothetical cohorts of women and men with small gallbladder polyps, with varying age (66-80 years) and comorbidity level (none, mild, moderate, severe). Drawing from current evidence, in the base case, we assumed no increased risk of gallbladder cancer in patients with small gallbladder polyps. To estimate maximal possible LE gains from surveillance, we assumed perfect cancer control consequent to 5 years of surveillance. We varied key assumptions including cancer risk and test performance characteristics in sensitivity analysis.

RESULTS

Projected LE gains from surveillance were <3 days across most cohorts and scenarios evaluated. For 66- and 80-year-olds with no comorbidities, LE gains were 1.46 and 1.45 days, respectively, for women, and 0.67 and 0.75 days for men. With 10 years of surveillance, LE gains increased to 2.94 days for 66-year-old women with no comorbidities (men: 1.35 days). If we assumed a 10% increase in gallbladder cancer risk among individuals with polyps, LE gains increased slightly to 1.60 days for 66-year-old women with no comorbidities (men: 0.74 days). Results were sensitive to test performance and surgical mortality.

DISCUSSION

Even under unrealistic, optimistic assumptions of cancer control, ultrasound surveillance of incidentally detected small gallbladder polyps provided limited benefit.

Advances in the Early Detection of Hepatobiliary Cancers

Hepatocellular cancer (HCC) and biliary tract cancers (BTCs) have poor survival rates and a low likelihood of a cure, especially in advanced-stage disease. Early diagnosis is crucial and can significantly improve survival rates through curative treatment approaches. Current guidelines recommend abdominal ultrasonography (USG) and alpha-fetoprotein (AFP) monitoring for HCC screening in high-risk groups, and abdominal USG, magnetic resonance imaging (MRI), and magnetic resonance cholangiopancreatography (MRCP) monitoring for biliary tract cancer. However, despite this screening strategy, many high-risk individuals still develop advanced-stage HCC and BTC. Blood-based biomarkers are being developed for use in HCC or BTC high-risk groups. Studies on AFP, AFP-L3, des-gamma-carboxy prothrombin, glypican-3 (GPC3), osteopontin (OPN), midkine (MK), neopterin, squamous cell carcinoma antigen (SCCA), Mac-2-binding protein (M2BP), cyclic guanosine monophosphate (cGMP), and interleukin-6 biomarkers for HCC screening have shown promising results when evaluated individually or in combination. In the case of BTCs, the potential applications of circulating tumor DNA, circulating microRNA, and circulating tumor cells in diagnosis are also promising. These biomarkers have shown potential in detecting BTCs in early stages, which can significantly improve patient outcomes. Additionally, these biomarkers hold promise for monitoring disease progression and evaluating response to therapy in BTC patients. However, further research is necessary to fully understand the clinical utility of these biomarkers in the diagnosis and management of HCC and BTCs.

Imaging of Hepatobiliary Cancer

The liver and biliary tree are common sites of primary and secondary malignancies. MRI followed by CT is the mainstay for the imaging characterization of these malignancies with the dynamically acquired contrast enhanced phases being the most important for diagnosis. The liver imaging reporting and data system classification provides a useful framework for reporting lesions in patents with underlying cirrhosis or who are at high risk for developing hepatocellular carcinoma. Detection of metastases is improved with the use of liver specific MRI contrast agents and diffusion weighted sequences. Aside from hepatocellular carcinoma, which is often diagnosed noninvasively, other primary hepatobiliary tumors may require biopsy for definite diagnosis, especially when presenting with nonclassic imaging findings. In this review, we examine the imaging findings of common and less common hepatobiliary tumors.

RadioGraphics Update: New Follow-up and Management Recommendations for Polypoid Lesions of the Gallbladder

Editor's Note.-RadioGraphics Update articles supplement or update information found in full-length articles previously published in RadioGraphics. These updates, written by at least one author of the previous article, provide a brief synopsis that emphasizes important new informaion such as technological advances, revised imaging protocols, new clinical guidelines involving imaging, or updated classification schemes.

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.

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.

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.

Survey Study on the Experience, Practice Patterns, and Preferences of the Fellows of the Society of Radiologists in Ultrasound for Evaluation and Management of Gallbladder Polyps Detected With Ultrasound

ABSTRACT

Gallbladder polyps (GPs) are a common incidental finding on ultrasound; however, important differences in recommended management exist among professional society guidelines.An electronic survey was sent to 189 fellows of the Society of Radiologists in Ultrasound. Main outcomes included preferences and current practice patterns for evaluation, management, and surveillance of GPs as well as personal lifetime experience with gallbladder sonography and GPs.A total of 64 subjects (34%) with experience in gallbladder sonography completed the study. The estimated combined total number of gallbladder scans seen by the responders was 3,071,880. None of fellows had ever seen a pedunculated GP <1 cm detected on ultrasound that was proven to be malignant at the time of detection or during subsequent follow-up. All of the fellows used size as a feature to stratify recommendations. The median size threshold currently used by Society of Radiologists in Ultrasound fellows for recommending ultrasound follow-up was 6 mm, and their preferred threshold was 7 mm. The median size threshold for recommending surgical consultation was 10 mm, and the preferred threshold was 10 mm. Wall thickening and shape were considered important factors by 76% and 67% of respondents, respectively.Society of Radiologists in Ultrasound fellows tend to provide recommendations most similar to the American College of Radiology and Canadian Association of Radiology guidelines for management of GPs. Many would prefer guidelines that result in fewer recommendations for follow-up and surgical consultation. Despite a substantial combined experience, this survey did not uncover any case of a small GP that was malignant.

Gallbladder Intramucosal Carcinoma Arising in a Cholesterol Polyp: A Case Report

Cholesterol polyp is the most common benign disease of gallbladder polyps, and is considered not to be the origin of malignancy. Herein, we report a rare case of a well-differentiated adenocarcinoma arising in a gallbladder cholesterol polyp. A pedunculated mulberry-like gallbladder polyp diagnosed with a cholesterol polyp preoperatively consisted of two distinct components macroscopically: a yellow-whitish lobulated lesion and a brownish irregular lesion. Microscopically, the former revealed to be a cholesterol polyp, but the latter demonstrated a well-differentiated adenocarcinoma. Even if imaging findings suggest a gallbladder cholesterol polyp, it is important to keep in mind that carcinoma can coexist like our case.

Longitudinal Ultrasound Assessment of Changes in Size and Number of Incidentally Detected Gallbladder Polyps

BACKGROUND. Previous European multisociety guidelines recommend routine follow-up imaging of gallbladder polyps (including polyps < 6 mm in patients without risk factors) and cholecystectomy for polyp size changes of 2 mm or more. OBJECTIVE. The purpose of this study was to assess longitudinal changes in the number and size of gallbladder polyps on serial ultrasound examinations. METHODS. This retrospective study included patients who underwent at least one ultrasound examination between January 1, 2010, and December 31, 2020 (as part of a hepatocellular carcinoma screening and surveillance program) that showed a gallbladder polyp. Number of polyps and size of largest polyp were recorded based primarily on review of examination reports. Longitudinal changes on serial examinations were summarized. Pathologic findings from cholecystectomy were reviewed. RESULTS. Among 9683 patients, 759 (8%) had at least one ultrasound examination showing a polyp. Of these, 434 patients (248 men, 186 women; mean age, 50.6 years) had multiple examinations (range, 2-19 examinations; mean, 4.8 examinations per patient; mean interval between first and last examinations, 3.6 ± 3.1 [SD] years; maximum interval, 11.0 years). Among these 434 patients, 257 had one polyp, 40 had two polyps, and 137 had more than two polyps. Polyp size was 6 mm or less in 368 patients, 7-9 mm in 52 patients, and 10 mm or more in 14 patients. Number of polyps increased in 9% of patients, decreased in 14%, both increased and decreased on serial examinations in 22%, and showed no change in 55%. Polyp size increased in 10% of patients, decreased in 16%, both increased and decreased on serial examinations in 18%, and showed no change in 56%. In 9% of patients, gallbladder polyps were not detected on follow-up imaging; in 6% of patients, gallbladder polyps were not detected on a follow-up examination but were then detected on later studies. No gallbladder carcinoma was identified in 19 patients who underwent cholecystectomy. CONCLUSION. Gallbladder polyps fluctuate in size, number, and visibility over serial examinations. Using a 2-mm threshold for growth, 10% increased in size. No carcinoma was identified. CLINICAL IMPACT. European multisociety guidelines that propose surveillance of essentially all polyps and a 2-mm size change as the basis for cholecystectomy are likely too conservative for clinical application.

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.

[Recent Updates on Diagnosis, Treatment, and Follow-up of Gallbladder Polyps]

A gallbladder (GB) polyp is an elevation of the GB mucosa that protrudes into the GB lumen. GB polyps have an estimated prevalence of 0.3-9.5% and can be divided into neoplastic (true) polyps and nonneoplastic polyps (pseudopolyps). Pseudopolyps are most commonly cholesterol polyps but also include focal adenomyomatosis and inflammatory polyps with no malignant potential. Neoplastic polyps, however, can be benign or malignant. Benign polyps are most commonly adenomas, while malignant polyps are usually adenocarcinoma. Transabdominal ultrasonography is the main radiological modality used for diagnosing and surveilling GB polyps. On the other hand, because it is difficult to diagnose GB polyps before surgery, alternative imaging modalities, such as endoscopic ultrasound, are being further evaluated. The current guidelines recommend cholecystectomy for GB polyps ≥ 10 mm in size as well as suboptimal sized GB polyps (6-9 mm) with other risk factors, including age >50, sessile, and symptoms. The quality of the evidence behind this practice is relatively low. Therefore, this review identifies the current gaps in the available evidence and guidelines and introduces methods that can help make decisions regarding patients who require a cholecystectomy or follow-up.

Genomic characterization of co-existing neoplasia and carcinoma lesions reveals distinct evolutionary paths of gallbladder cancer

Gallbladder carcinoma is the most common cancer of the biliary tract with dismal survival largely due to delayed diagnosis. Biliary tract intraepithelial neoplasia (BilIN) is the common benign tumor that is suspected to be precancerous lesions. However, the genetic and evolutionary relationships between BilIN and carcinoma remain unclear. Here we perform whole-exome sequencing of coexisting low-grade BilIN (adenoma), high-grade BilIN, and carcinoma lesions, and normal tissues from the same patients. We identify aging as a major factor contributing to accumulated mutations and a critical role of CTNNB1 mutations in these tumors. We reveal two distinct carcinoma evolutionary paths: carcinoma can either diverge earlier and evolve more independently or form through the classic adenoma/dysplasia-carcinoma sequence model. Our analysis suggests that extensive loss-of-heterozygosity and mutation events in the initial stage tend to result in a cancerous niche, leading to the subsequent BilIN-independent path. These results reframes our understanding of tumor transformation and the evolutionary trajectory of carcinogenesis in the gallbladder, laying a foundation for the early diagnosis and effective treatment of gallbladder cancer.

The progression from biliary tract intraepithelial neoplasia (BilIN) to gallbladder carcinoma (GBC) remains unclear. Here the authors use genomics to analyze coexisting GBC lesions, low-grade and high-grade BilINs, revealing two distinct evolutionary paths for GBC development.

Comment on gallbladder polyps: Correlation of size and clinicopathologic characteristics based on updated definitions

• There was strong correlation between polyp diameter (≥ 10 mm vs <10 mm) and the risk of gallbladder cancer (OR=54; r=0.704). • There was moderate correlation between polyp diameter (10-19 mm vs <10 mm) and the risk of gallbladder cancer (OR=23; r=0.534). • There was moderate correlation between polyp diameter (≥ 20 mm vs <20 mm) and the risk of gallbladder cancer (OR=300; r=0.559). • There was moderate correlation between polyp diameter (≥ 20 mm vs <10 mm) and the risk of gallbladder cancer (OR=551; r=0.697). • Our results suggest that as the diameter of the polyp reaches 20 mm, it is necessary to plan a surgical treatment strategy as if the patient has gallbladder cancer.

Malignancy in elective cholecystectomy due to gallbladder polyps or thickened gallbladder wall: a single-centre experience

INTRODUCTION

Gallbladder cancer is a rare but aggressive malignancy. Surgical resection is recommended for gallbladder polyps ≥10 mm. For gallbladder wall thickening, resection is recommended if malignancy cannot be excluded. The incidence of gallbladder malignancy after cholecystectomy with indications of polyps or wall thickening in the Swedish population is not known.

MATERIAL/METHODS

A retrospective study was performed at Linköping University Hospital and included patients who underwent cholecystectomy 2010 - 2018. All cholecystectomies performed due to gallbladder polyps or gallbladder wall thickening without other preoperative malignant signs were identified. Preoperative radiological examinations were re-analysed by a single radiologist. Medical records and histopathology reports were analysed.

RESULTS

In all, 102 patients were included, of whom 65 were diagnosed with gallbladder polyps and 37 with gallbladder wall thickening. In each group, one patient (1.5% and 2.7% in each group) had gallbladder malignancy ≥ pT1b.Two (3.1%) and three (8.1%) patients with gallbladder malignancy < T1b were identified in each group.

DISCUSSION/CONCLUSION

This study indicates that the incidence of malignancy is low without other malignant signs beyond gallbladder polyps and/or gallbladder wall thickening. We propose that these patients should be discussed at a multidisciplinary tumour board. If the polyp is 10-15 mm or if the gallbladder wall is thickened but no other malignant signs are observed, cholecystectomy can be safely performed by an experienced general surgeon at a general surgery unit. If the histopathology indicates ≥ pT1b, the patient should be referred immediately to a hepatobiliary centre for liver and lymph node resection.

Management of gallbladder polyps

A gallbladder polyp (GP) is defined as an elevation of the gallbladder mucosa that protrudes into the gallbladder lumen. Gallbladder polyps (GPs) have an estimated prevalence in adults of 0.3–12.3%. However, only 5% of polyps are considered “true” GPs that have malignant potential or are even already cancerous. The most important imaging method for diagnosis and follow-up of GPs is transabdominal ultrasound, but it fails to discriminate between true and pseudo polyps at a clinically relevant level. Although gallbladder cancer (GBC) arising from polyps is a rare event, malignancy is significantly more common among polyps from a size of 10 mm. In light of this, the consensus, which is reflected in current guidelines, is that surgery should be considered for polyps of 10 mm or greater. However, 10 mm is an arbitrary cutoff, and high-quality evidence to support this is lacking. Lowering the threshold for cholecystectomy when patients have additional risk factors for gallbladder malignancy may improve the cancer detection rate in polyps smaller than 10 mm. Nevertheless, the evidence behind this is also weak. This review shows the shortcomings in the available evidence and underlines the decision-making process regarding the surgical indication, surveillance, or both.