The hyperplastic cholecystoses: cholesterolosis and adenomyomatosis

Spectrum of imaging findings in hyperplastic cholecystosis and potential mimics

Adenomyomatosis and cholesterolosis of the gallbladder, collectively termed hyperplastic cholecystosis, are commonly encountered incidental findings on imaging studies performed for a variety of indications including biliary colic or nonspecific abdominal pain. These pathologies are rarely the source of symptoms, generally considered benign and do not require further work-up. However, their imaging characteristics can overlap with more sinister conditions that should not be missed. In this review, the imaging findings of adenomyomatosis and cholesterolosis will be reviewed followed by other gallbladder pathologies that might mimic these conditions radiologically. Important differentiating factors will be discussed that can aid the radiologist in making a more confident imaging diagnosis.

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

KEY POINTS

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

Photoacoustic Imaging for Differential Diagnosis of Benign Polyps versus Malignant Polyps of the Gallbladder: A Preliminary Study

OBJECTIVE

To investigate the feasibility of ex vivo multispectral photoacoustic (PA) imaging in differentiating cholesterol versus neoplastic polyps, and benign versus malignant polyps, of the gallbladder.

MATERIALS AND METHODS

A total of 38 surgically confirmed gallbladder polyps (24 cholesterol polyps, 4 adenomas, and 10 adenocarcinomas) from 38 patients were prospectively included in this study. The surgical specimens were set on a gel pad immersed in a saline-filled container. The PA intensities of polyps were then measured, using two separate wavelength intervals (421-647 nm and 692-917 nm). Mann-Whitney U test was performed for the comparison of normalized PA intensities between the cholesterol and neoplastic polyps, and between the benign and malignant polyps. Kruskal-Wallis test was conducted for the comparison of normalized PA intensities among the cholesterol polyps, adenomas, and adenocarcinomas.

RESULTS

A significant difference was observed in the normalized PA intensities between the cholesterol and neoplastic polyps at 459 nm (median, 1.00 vs. 0.73; p = 0.032). Comparing the benign and malignant polyps, there were significant differences in the normalized PA intensities at 765 nm (median, 0.67 vs. 0.78; p = 0.013), 787 nm (median, 0.65 vs. 0.77; p = 0.034), and 853 nm (median, 0.59 vs. 0.85; p = 0.028). The comparison of the normalized PA intensities among cholesterol polyps, adenomas, and adenocarcinomas demonstrated marginally significant differences at 765 nm (median, 0.67 vs. 0.66 vs. 0.78, respectively; p = 0.049).

CONCLUSION

These preliminary results indicate that benign versus malignant gallbladder polyps might exhibit different spectral patterns on multispectral PA imaging.

A literature review of radiological findings to guide the diagnosis of gallbladder adenomyomatosis

BACKGROUND

Gallbladder adenomyomatosis (GA) is a benign gallbladder entity discovered as an asymptomatic gallbladder mass. Since gallbladder cancer is in the differential diagnosis for gallbladder masses, the ability to differentiate benign disease avoids a more extensive oncologic resection. This study sought to review imaging modalities used to diagnose GA.

METHODS

PubMed and SciVerse Scopus were systematically searched using the terms: "gallbladder adenomyomatosis" and "gallbladder imaging" for articles published between January 2000 and January 2015.

RESULTS

A total of 14 articles were reviewed in this analysis. Contemporary series report the use of ultrasound (US), computed tomography (CT) or magnetic resonance imaging (MRI) in GA imaging. Ultrasound detection of Rokitansky-Aschoff sinuses, visualized as small cystic spaces with associated "comet-tail" or "twinkling" artifact, is pathognomonic for GA. A "Pearl-Necklace" sign of small connected sinuses on MRI or "Rosary" sign on CT are additional characteristics that may assist in establishing a diagnosis.

CONCLUSION

Ultrasound is the most commonly used tool to investigate GA. If not diagnostic, CT or MRI are effective in attempting to differentiate a benign or malignant cholecystic mass. Characteristic signs should lead the surgeon to perform a laparoscopic cholecystectomy in symptomatic patients or manage non-operatively in asymptomatic patients.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

Retrospective single-center study.

SETTING

University teaching hospital.

PATIENTS

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

RESULTS

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

LIMITATIONS

Retrospective review of selected patients from a tertiary medical center.

CONCLUSIONS

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

Imaging of adenomyomatosis of the gall bladder

Adenomyomatosis is a relatively common abnormality of the gall bladder, with a reported incidence of between 2.8 and 5%. Although mainly confined to the adult study group, a number of cases have been reported in the paediatric study group. It is characterized pathologically by excessive proliferation of the surface epithelium and hypertrophy of the muscularis propria of the gall bladder wall, with invagination of the mucosa into the thickened muscularis forming the so-called 'Rokitansky-Aschoff' sinuses. The condition is usually asymptomatic and is often diagnosed as an incidental finding on abdominal imaging. The radiological diagnosis is largely dependent on the visualization of the characteristic Rokitansky-Aschoff sinuses. As the condition is usually asymptomatic, the importance of making a correct diagnosis is to prevent misinterpretation of other gall bladder conditions such as gall bladder cancer, leading to incorrect treatment. In the past, oral cholecystography was the main imaging method used to make this diagnosis. In most institutions, oral cholecystography is no longer carried out, and the diagnosis is now more commonly seen on cross-sectional imaging. In this review article, we describe the manifestations of adenomyomatosis on the various imaging methods, with an emphasis on more modern techniques such as magnetic resonance cholangiopancreatography. A brief section on oral cholecystography to aid readers familiar with this technique in understanding the comparable imaging features on more modern imaging techniques is included.

Outcome of gall bladder polypoidal lesions detected by transabdominal ultrasound scanning: A nine year experience

AIM: To determine the outcome of polypoidal lesions within the gall bladder (PLG) diagnosed by trans-abdominal scanning.

METHODS: A nine-year (1993-2002) retrospective case-note review of all patients who underwent ultrasound scanning after referral to a single Upper GI Surgeon at a District General Hospital was conducted. Patients who were diagnosed with a PLG were included in our study. A database was constructed and patient details, investigations including ultrasound scan (USS) findings, treatment and histology and final diagnosis were recorded.

RESULTS: Twenty-three (out of 651) patients were diagnosed pre-operatively by USS to have a polyp-like gall bladder lesion (PLG). Post cholecystectomy histological examination revealed 12 gallstones, 7 cholesterol polyps, 3 adenocarcinomas within polyps and 1 normal gall bladder. The specificity of USS in the diagnosis of PLG was 92.3%. All the true polyps were malignant. Overall USS had 66.66% sensitivity and 100% specificity in the pre-operative suspicion of malignancy. Using size greater than 10 mm as measured on USS as a cut-off, we find 100% sensitivity and 86.95% specificity with a positive predictive value of 50% in the diagnosis of malignancy in PLG.

CONCLUSION: A large number of PLG are in fact calculi within diseased gall bladder. In cases of gall bladder polyps more then 10 mm in size on USS further imaging (cross-sectional and/or EUS) is indicated prior to surgery. This will help in the optimal management of patients and avoid histological surprises.

Ultrasonography in the diagnosis of true gallbladder polyps: the contradiction in the literature

Polypoid lesions of the gallbladder (PLGs) are often incidentally identified during ultrasonographic examination of abdominal pain. The present study was designed to determine the reliability of ultrasonography (US) in the diagnosis of PLGs. The records of 853 patients who underwent laparoscopic cholecystectomy (LC) for PLGs in Gazi Medical School from January 2000 to January 2004 were reviewed. Data were collected regarding the patients' gender, age, symptoms, serum lipid levels, the size and the number of polyps on US, surgical indications for PLGs and histopathological diagnosis. In all, 56 of 853 patients had PLGs and underwent LC. Right upper quadrant pain (59%) was the most common presenting symptom that led to gallbladder US. Nearly 75% of the lesions were smaller than 10 mm. At histopathologic examination cholesterolosis was found in 17 of 56 (30%) patients, and 12 of 56 (21%) demonstrated only cholelithiasis; 17 (30%) patients had both cholesterolosis and stones. Only 10 (18%) patients had adenomatous polyp and 8 of these polyps were larger than 1 cm. Overall US-based diagnosis of gallbladder polyp was inaccurate in 82%. The sensitivity and specificity of US for polyps <1 cm was 20% and 95.1%, respectively, whereas the sensitivity and specificity of US for polyps >1 cm was 80% and 99.3%, respectively. The accuracy of US in diagnosing PLGs was poor, especially in polyps <1 cm.

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

BACKGROUND AND OBJECTIVES

The purpose of this paper is to evaluate the utility of positron emission tomography (PET) with fluorine-18-labeled fluoro-deoxyglucose (FDG) in the preoperative differential diagnosis of gallbladder tumors. We performed PET studies of gallbladder tumors in order to predict the malignancy of these tumors preoperatively.

METHODS

Sixteen patients who had protuberant lesions in the gallbladder and who were scheduled to undergo surgery were studied with PET using FDG. Focally increased FDG uptake in the gallbladder region was considered malignant. The FDG-PET findings were compared with the histological findings of surgical pathology.

RESULTS

Sensitivity of FDG-PET was 75% (6/8 patients). One of two false-negative cases suffered from diabetes mellitus, and in the other case, the lesion was small. Specificity was 87.5% (7/8 patients). A case with xanthogranulomatous cholecystitis (XGC) was the only false-positive case.

CONCLUSIONS

FDG-PET may be able to provide important information for evaluating the malignancy of gallbladder tumors.

Ultrasonography

Diagnostic sonography is experiencing a breath-taking period of technological advancement. Ultrasound contrast agents, new imaging techniques, and handheld instruments will play a role in facilitating more diagnostic power in high-end imaging and insuring more widespread use of diagnostic sonography in medicine in general.

MR imaging of the gallbladder

T2-weighted imaging and MRCP, which have high sensitivity to edema and fluid, are paramount in the evaluation of certain gallbladder diseases, such as cholelithiasis, cholecystitis, adenomyomatosis, and cystic duct abnormalities. Dynamic gadolinium-enhanced MR imaging has the potential to differentiate among the many nonspecific-appearing lesions involving the gallbladder. MR imaging may not yet replace ultrasound as the workhorse of acute gallbladder imaging. Currently, MRCP is an ideal complementary study to inconclusive sonographic studies and can help plan surgical intervention in the setting of acute cholecystitis. Further investigation of hepatobiliary contrast agents, however, may reveal that MR imaging may be considered as first-line imaging in the acute setting.

Adenomyomatosis with Marked Subserosal Fibrosis and Lipomatosis of the Gallbladder: Mural Stratification Demonstrated with MR

The authors reported a case of fundal-type adenomyomatosis in which mural stratification corresponding to histopathological findings was clearly demonstrated with MR imaging. Single-shot fast spin echo images for MR cholangiopancreatography clearly visualized Rokitansky-Aschoff sinuses (RAS), which are a diagnostic clue for this disease. However, mural stratification comprising RAS with muscular proliferation, massive fibrosis and subserosal fat deposition was more precisely demonstrated in T(2)-weighted images obtained with fast spin echo.

Ultrasonography incorrectly diagnoses gallbladder polyps

To determine the accuracy of ultrasound-diagnosed polypoid lesions of the gallbladder in their institution, the authors reviewed the records of 41 patients with polypoid lesions of the gallbladder who underwent cholecystectomy, and collected data concerning age, sex, symptoms, and histopathologic diagnosis. Histopathologic evaluation confirmed polyps in only two patients (4.9%) categorized as having polypoid lesions of the gallbladder. Most specimens from patients with ultrasonography reports suggesting small polyps manifested cholesterolosis (17 of 41) or cholelithiasis (15 of 41). No specimen harbored malignancy. Mean patient age was 47.4 years, and the most common symptoms were pain (85%), nausea (44%), vomiting (29%), and abnormal liver function test results (14%). The accuracy of sonography for diagnosing polypoid lesions of the gallbladder was poor. Many of the small polyps seen on sonography most likely represented a stone embedded in the gallbladder wall or other abnormality. Because of the likelihood of cholelithiasis, the authors recommend that patients with biliary symptoms and ultrasonography findings suggesting polypoid lesions of the gallbladder undergo cholecystectomy.

Adenomyomatosis of the gallbladder with subserosal fatty proliferation: CT findings in two cases

Adenomyomatosis of the gallbladder is frequently seen in ordinary operative specimens. Subserosal fat may proliferate in the presence of adenomyomatosis, but the amount of subserosal fat may be quite variable. Typical and atypical computed tomographic (CT) findings in two cases of adenomyomatosis with subserosal fatty proliferation of the gallbladder are presented. The thick fatty layer surrounding the thickened gallbladder wall with intramural diverticula and stones, typical of CT findings, was seen in one case, and fat interspersed in the periphery of the thickened gallbladder wall without intramural stones, atypical of CT findings, was seen in a second case.

Case report--CT findings in adenomyomatosis of the gallbladder

A case report of the CT findings in adenomyomatosis of the gallbladder is presented. Significant CT findings of this entity are variation in wall density, marked differential enhancement of wall layers during dynamic liver scanning and detection of Rokitansky-Aschoff sinuses within the wall. CT apparently depicts both mucosal and muscularis thickening.

The usefulness and limitations of ultrasonography for the diagnosis of adenomyomatosis of the gallbladder

Ultrasonography has been popular for the diagnosis of gallbladder diseases since the mid-1970s. Although this technique has replaced oral cholecystography (OCG) for the diagnosis of cholecystolithiasis, it has not gained popularity in the diagnosis of adenomyomatosis of the gallbladder (AMMG). We examined 141 patients with clinically suspected gallbladder disease. Ultrasonography (previously done by a radiologist) had produced no positive findings. On ultrasonographic re-evaluation by the same radiologist, but in the presence of a surgeon from our study group, 64 cases of AMMG were detected. OCG revealed the diagnosis of AMMG in 13 other cases. In the study group there were no false-positive results. However, the false-negative rate of sonography in diagnosing AMMG was 16.9%. Thus, in our opinion ultrasonography is a worthwhile technique in diagnosing AMMG done by a surgeon.

Acalculous disease of the gall bladder

Images

Diverticular disease (adenomyomatosis) of the gallbladder: a radiological-pathological survey

Seventy consecutive gallbladders removed at surgery were examined radiologically and pathologically. Fifteen (21%) of the operative specimens showed naked-eye changes of adenomyomatosis. The main conclusions drawn from this study are that this abnormality is present in a much higher proportion of gallbladders removed at surgery than is generally realised, and that the pathogenesis is primarily an abnormality of muscle contractions, with a strong similarity to diverticular disease of the colon. Diverticular disease of the gallbladder might well be the most appropriate name for this condition. The results of a post-operative clinical assessment of patients with diverticular disease are also presented. But this represents a small number of patients and larger, perhaps multicentre, surveys would be required in order to assess the clinical significance of this interesting abnormality.

Cholecystokinetic cholecystography

A prospective clinical trial of 100 patients receiving either intramuscular ceruletide or a fatty meal to contract the gallbladder after oral cholecystography is described. The percentage reduction of the gallbladder area after 30 min of stimulation was not significantly greater with ceruletide (49%) than with a fatty meal (44%) (t-test: p greater than 0.3). Ceruletide caused significantly more adverse reactions than a fatty meal (Fisher test, p less than 0.01). The diagnostic value of routine cholecystokinetic stimulation is doubtful, since the diagnosis changed after the contraction in only 1 patient.

Gallbladder disease in the morbidly obese

During a 7 year period, 200 consecutive morbidly obese patients underwent a standardized gastric exclusion procedure. Group A was composed of the first 120 patients and Group B of the last 80 patients. In Group A, 22 patients had undergone a previous cholecystectomy and 12 patients had a cholecystectomy at the time of gastric exclusion because of positive diagnostic studies or palpation of stones. Of the remaining 87 patients in this initial group who were at risk for the development of gallbladder disease, 24 (27.6 percent) required a cholecystectomy in the first 3 postoperative years (mean 15.6 months). Twelve patients had acute cholecystitis, 3 patients had choledocholithiasis, and 1 patient had acute gallstone pancreatitis. In Group B, 18 patients had a previous cholecystectomy, 15 had positive diagnostic studies (ultrasonography and oral cholecystography) preoperatively, and 47 had negative studies. Cholecystectomy was routinely performed at the time of gastric exclusion surgery in the 62 patients with gallbladders in Group B. Of the 47 patients who had normal preoperative diagnostic studies, 40 (85.1 percent) had abnormal histologic findings in the gallbladder. Only seven patients in Group B had a normal gallbladder (14.7 percent). We conclude that gallbladder disease is considerably more frequent in the morbidly obese population (91.3 percent) than has previously been recognized, that diagnostic studies are frequently inaccurate, and that postoperative gallbladder disease is common (28.7 percent). On the basis of these results, routine cholecystectomy at the time of gastric exclusion surgery is recommended.

The fatty meal and acalculous gall-bladder disease

The practice of routinely obtaining after fatty meal films during oral cholecystography has been questioned. A retrospective analysis of 45 cases of adenomyomatosis or polyps revealed that, in 28% of patients with adenomyomatosis, the gall-bladder appeared entirely normal before fat. It is concluded that, for the detection of acalculous gall-bladder disease, the fatty meal should be a routine part of oral cholecystography.