Contrast-enhanced ultrasound to assess gallbladder polyps

PURPOSE

To assess the value of contrast-enhanced ultrasound (CEUS) in distinguishing adenomatous gallbladder polyps from cholesterol gallbladder polyps.

METHODS

A total of 164 patients with gallbladder polyps were retrospectively analyzed. All patients underwent B-mode ultrasound (US) and CEUS before cholecystectomy. Gallbladder polyps were divided into cholesterol polyp group and adenomatous polyp group according to pathology. Differences in patient's age, gender, maximum polyp size, number, presence of gallstones, vascularity and stalk width measured by US and vascular stalk width measured by CEUS were tested between the two groups. The diagnostic performance of specific US features was evaluated. The independent factors related with adenomatous polyps were analyzed by multiple logistic regression analyses.

RESULTS

There were 114 cholesterol polyps and 50 adenomatous polyps in 164 patients analyzed in the study. Differences in maximum size, vascularity, and stalk width of the gallbladder polyp were significant between the two groups (p < 0.05), whereas differences in patient's age, gender, number of gallbladder polyp, and presence of gallstones between the two groups were not (p > 0.05). Stalk width was wider than vascular stalk width between the two groups (p < 0.05). Vascular stalk width was also statistically different between the two groups (p < 0.05). The diagnostic performance of vascular stalk width was more significant than stalk width. Only vascular stalk width and vascularity were independent factors related with adenomatous polyps.

CONCLUSION

Vascular stalk width measured by CEUS is more accurate than stalk width measured by grayscale US in distinguishing adenomatous polyps from cholesterol polyps.

Effect of gallbladder polyp size on the prediction and detection of gallbladder cancer

BACKGROUND

Gallbladder polyps are relatively common. Although most gallbladder polyps are benign, some are malignant. Current guidelines state that malignancy should be suspected for polyps ≥ 10 mm in diameter. We clarified the cancer detection rates in accordance with the size distribution of gallbladder polyps, and evaluated the effectiveness of the reported risk factors in predicting malignancy.

METHODS

In this retrospective case-control study, our institutional database was searched to identify patients who underwent laparoscopic cholecystectomy for benign or malignant gallbladder polyps at Sada Hospital, Japan. The chi-squared test was used to analyze the risk factors for malignancy.

RESULTS

There were 227 protruding gallbladder lesions. The 206 benign polyps had a diameter of 2-21 mm, while the 21 malignant polyps were 7-60 mm. The cancer detection rates were 16.4% for lesions ≥ 10 mm, 55.9% for lesions ≥ 15 mm, and 94.1% for lesions ≥ 20 mm. Of the benign lesions, cholesterol polyps were the most frequent (50-100%) in all size ranges, even in large lesions (≥ 15 mm). The sessile lesion morphology was significantly more frequent in malignant (60%) than benign lesions (3.4%, p < 0.00001). Multiple polyps were frequently diagnosed not only as cholesterol polyps (81.1%), but also as adenomas (60%); adenomas were found as a single adenoma within other types of polyps. There were two cases of malignant small gallbladder polyps (< 10 mm); these lesions met the surgical indications of a size increase during observation or a sessile morphology.

CONCLUSIONS

The cancer detection rate increased significantly with an increase in the lesion size. Risk factors such as a sessile polyp morphology or an increase in lesion size were effective in predicting malignancy for small gallbladder polyps. It might be difficult to accurately predict the pathologic diagnoses of gallbladder polyps preoperatively, as cholesterol polyps were most frequent, even in the large size range.

Bile cholesterol and viscosity, the keys to discriminating adenomatous polyps from cholesterol polyps by a novel predictive scoring model

Background

Adenomatous gallbladder polyps, premalignant lesions of the gallbladder, have fatal outcomes, whereas cholesterol polyps have benign features. Herein, we proposed a novel, predictive scoring model of adenomatous polyps to distinguish them from cholesterol polyps, by analyzing bile components and bile viscosity.

Methods

Patients with gallbladder polyp pathologically confirmed after cholecystectomies were analyzed. After dividing patients into two groups (adenomatous or cholesterol polyps), the clinicopathologic profiles and bile nature, including components and viscosity were compared and a predictive scoring model for adenomatous polyps was assessed.

Results

Eleven adenomatous polyps and 96 cholesterol polyps were analyzed. The variables significantly associated with adenomatous polyps were age > 55 years (OR = 23.550, p = 0.020), bile viscosity< 7.5 s^− 1 (OR = 22.539, p = 0.012), and bile cholesterol< 414.5 mg/dl (OR = 10.004, p = 0.023) and the points for each variable in the predictive scoring model were allocated as 3, 3, and 2, respectively. Final scores ranged from 0 to 8 points and the best performance of model at a cutoff of ≥6 points had 90.9% of sensitivity and 80.2% of specificity.

Conclusions

Bile viscosity and bile cholesterol accompanied by age were revealed as significant predictors of adenomatous polyps, distinguishing them from cholesterol polyps of gallbladder. It can be the cornerstone for creating accurate guidelines for preoperatively determining treatment strategies of gallbladder polyps.

Benign gallbladder diseases: Imaging techniques and tips for differentiating with malignant gallbladder diseases

Benign gallbladder diseases usually present with intraluminal lesions and localized or diffuse wall thickening. Intraluminal lesions of the gallbladder include gallstones, cholesterol polyps, adenomas, or sludge and polypoid type of gallbladder cancer must subsequently be excluded. Polyp size, stalk width, and enhancement intensity on contrast-enhanced ultrasound and degree of diffusion restriction may help differentiate cholesterol polyps and adenomas from gallbladder cancer. Localized gallbladder wall thickening is largely due to segmental or focal gallbladder adenomyomatosis, although infiltrative cancer may present similarly. Identification of Rokitansky-Aschoff sinuses is pivotal in diagnosing adenomyomatosis. The layered pattern, degree of enhancement, and integrity of the wall are imaging clues that help discriminate innocuous thickening from gallbladder cancer. High-resolution ultrasound is especially useful for analyzing the layering of gallbladder wall. A diffusely thickened wall is frequently seen in inflammatory processes of the gallbladder. Nevertheless, it is important to check for coexistent cancer in instances of acute cholecystitis. Ultrasound used alone is limited in evaluating complicated cholecystitis and often requires complementary computed tomography. In chronic cholecystitis, preservation of a two-layered wall and weak wall enhancement are diagnostic clues for excluding malignancy. Magnetic resonance imaging in conjunction with diffusion-weighted imaging helps to differentiate xathogranulomatous cholecystitis from gallbladder cancer by identifying the presence of fat and degree of diffusion restriction. Such distinctions require a familiarity with typical imaging features of various gallbladder diseases and an understanding of the roles that assorted imaging modalities play in gallbladder evaluations.

Clinical and radiologic preoperative predicting factors for GB cholesterol polyp

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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