Xanthogranulomatous cholecystitis mimicking gallbladder carcinoma with a false-positive result on fluorodeoxyglucose PET

Deep learning nomogram for preoperative distinction between Xanthogranulomatous cholecystitis and gallbladder carcinoma: A novel approach for surgical decision

The distinction between Xanthogranulomatous Cholecystitis (XGC) and Gallbladder Carcinoma (GBC) is challenging due to their similar imaging features. This study aimed to differentiate between XGC and GBC using a deep learning nomogram model built from contrast enhanced computed tomography (CT) scans. 297 patients were included with confirmed XGC (94) and GBC (203) as the training and internal validation cohort from 2017 to 2021. The deep learning model Resnet-18 with Fourier transformation named FCovResnet18, shows most impressive potential in distinguishing XGC from GBC using 3-phase merged images. The accuracy, precision and area under the curve (AUC) of the model were then calculated. An additional cohort of 74 patients consisting of 22 XGC and 52 GBC patients was enrolled from two subsidiary hospitals as the external validation cohort. The accuracy, precision and AUC achieve 0.98, 0.99, 1.00 in the internal validation cohort and 0.89, 0.92, 0.92 in external validation cohort. A nomogram model combining clinical characteristics and deep learning prediction score showed improved predicting value. Altogether, FCovResnet18 nomogram has demonstrated its ability to effectively differentiate XGC from GBC preoperatively, which significantly aid surgeons in making informed and accurate surgical decisions for XGC and GBC patients.

Usefulness of MRI Scoring System for Differential Diagnosis between Xanthogranulomatous Cholecystitis and Wall-Thickening Type Gallbladder Cancer

Purpose

To define an MRI scoring system for differentiating xanthogranulomatous cholecystitis (XGC) from wall-thickening type gallbladder cancer (GBC) and compare the diagnostic performance of the scoring system with the visual assessment of radiologists.

Materials and Methods

We retrospectively analyzed 23 and 35 patients who underwent abdominal MRI and were pathologically diagnosed with XGC and wall-thickening-type GBC after surgery, respectively. Three radiologists reviewed all MRI findings. We defined a scoring system using these MRI findings for differentiating XGC from wall-thickening type GBC and compared the area under the curve (AUC) of the scoring system with the visual assessment of radiologists.

Results

Nine MRI findings showed significant differences in differentiating the two diseases: diffuse gallbladder wall thickening (p < 0.001), mucosal uniformity (p = 0.002), intramural T2-high signal intensity (p < 0.001), mucosal retraction (p = 0.016), gallbladder stones (p < 0.001), T1-intermediate to high-signal intensity (p = 0.033), diffusion restriction (p = 0.005), enhancement pattern (p < 0.001), and phase of peak enhancement (p = 0.008). The MRI scoring system showed excellent diagnostic performance with an AUC of 0.972, which was significantly higher than the visual assessment of the reviewers.

Conclusion

The MRI scoring system showed better diagnostic performance than the visual assessment of radiologists to differentiate XGC from wall-thickening-type GBC.

Xanthogranulomatous cholecystitis in a patient with ulcerative colitis and primary sclerosing cholangitis: A case report

Chronic gallbladder disease due to xanthogranulomatous cholecystitis is uncommon, and its symptoms are generally vague. While there is no firm evidence to link xanthogranulomatous cholecystitis to primary sclerosing cholangitis or ulcerative colitis. The patient is a 41-year-old male with a history of ulcerative colitis, primary sclerosing cholangitis, and biliary stenting who complained of symptoms of anorexia, jaundice, and pruritus. In the initial ultrasound exam, there was evidence of intrahepatic and extra-hepatic bile duct dilation along with a significant and mass-like circumferential thickening of the gallbladder wall. Magnetic resonance cholangiopancreatography was performed for further evaluation, which indicated increased gallbladder wall thickness, containing multiple T2 hyper-signal nodules while the mucosal layer was intact. There was also a filling defect in the common bile duct's distal portion. These findings matched a xanthogranulomatous cholecystitis diagnosis and a possibly malignant lesion in the distal of the common bile duct. The patient ultimately had a cholecystectomy, and pathology findings confirmed the diagnosis of xanthogranulomatous cholecystitis. Biopsy specimens obtained from the distal of the common bile duct lesion were microscopically identified as intramucosal adenocarcinoma. In patients with a history of primary sclerosing cholangitis who present with nonspecific symptoms suggesting chronic gallbladder disease and radiologic evidence of circumferential gallbladder wall thickening containing intramural nodules and intact mucosa, xanthogranulomatous cholecystitis should be kept in mind.

Asymptomatic chronic suppurative cholecystitis and peritonitis mimicking metastasis by 18F-FDG PET/CT scan during sigmoid colon cancer surveillance

The study describes an unusual case that a patient with previous history of adenocarcinoma of sigmoid colon who has developed chronic suppurative cholecystitis and peritonitis was misdiagnosed as metastasis. This case is presented to illustrate the importance of considering benign etiologies that may mimic metastatic disease when interpreting positron emmision tomography (PET)/CT scans.

Xanthogranulomatous cholecystitis: Diagnosis and management

Xanthogranulomatous cholecystitis (XGC) is a rare form of cholecystitis, characterized by the presence of xanthogranuloma, prominent yellow structures within the gallbladder wall that is very often lithiasic. When XGC presents in its pseudo-tumoral form with occasional adjacent organ involvement, it can mimic gallbladder carcinoma (GBC). The etiopathogenesis of XGC is inflammatory destruction of Rokitansky-Aschoff sinuses containing biliary and cholesterol pigments within the gallbladder wall; this leads to a florid granulomatous histiocytic inflammatory reaction. The prevalence ranges from 1.3% to 8.8% of all cholecystectomies and varies from country to country; XGC occurs predominantly in patients over 50 years of age, and is equally distributed between males and females. Its association with GBC remains a topic of debate in the literature (between 0 and 20%). Symptoms are non-specific and generally similar to those of acute or chronic cholecystitis. XGC, when associated with altered health status, leads to the suspicion of GBC. XGC can also come to light due to an acute complication of cholecystolithiasis, in particular, gallstone migration. Imaging by sonography and CT scan is suggestive, but magnetic resonance imaging is more specific. In difficult cases, biopsy may be necessary to eliminate the diagnosis of tumor. In case of pre- or intra-operative diagnostic doubt, the opinion of a hepatobiliary specialty center can be of help. When diagnosis of GBC has been eliminated, laparoscopic cholecystectomy is recommended, although with a high risk of conversion to laparotomy and complications.

Xanthogranulomatous cholecystitis mimicking gallbladder cancer on 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan

The abnormal thickening of the gallbladder (GB) wall can be caused by a malignant condition like gallbladder carcinoma or by benign lesions such as chronic cholecystitis or xanthogranulomatous cholecystitis (XGC). Mural thickening is a common finding between them as fluorodeoxyglucose (FDG) can be taken up by inflammatory cells also. Here, we present a patient with irregular thickening of the GB wall which was suspected to of GB carcinoma since FDG positron emission tomography/computed tomography scan showed increased tracer uptake in the lesion. However, after surgery the histopathological report was suggestive of XGC.

Imaging-based algorithmic approach to gallbladder wall thickening

Gallbladder (GB) wall thickening is a frequent finding caused by a spectrum of conditions. It is observed in many extracholecystic as well as intrinsic GB conditions. GB wall thickening can either be diffuse or focal. Diffuse wall thickening is a secondary occurrence in both extrinsic and intrinsic pathologies of GB, whereas, focal wall thickening is mostly associated with intrinsic GB pathologies. In the absence of specific clinical features, accurate etiological diagnosis can be challenging. The survival rate in GB carcinoma (GBC) can be improved if it is diagnosed at an early stage, especially when the tumor is confined to the wall. The pattern of wall thickening in GBC is often confused with benign diseases, especially chronic cholecystitis, xanthogranulomatous cholecystitis, and adenomyomatosis. Early recognition and differentiation of these conditions can improve the prognosis. In this minireview, the authors describe the patterns of abnormalities on various imaging modalities (conventional as well as advanced) for the diagnosis of GB wall thickening. This paper also illustrates an algorithmic approach for the etiological diagnosis of GB wall thickening and suggests a formatted reporting for GB wall abnormalities.

Is Final Histopathological Examination the Only Diagnostic Criteria for Xanthogranulomatous Cholecystitis?

Background:

Xanthogranulomatous cholecystitis (XGC) is an uncommon inflammatory disease of gallbladder (GB) and can mimic GB cancer in extensive form. This study aims to assess the predictability of XGC on the basis of clinical presentation, laboratory tests, and radiological or intraoperative findings on frozen section analysis.

Materials and Methods:

This is a retrospective study, conducted over a period of 4 years from October 2013 to November 2017. In this study, all patients with histopathological reports of XGC, who underwent cholecystectomy or a radical cholecystectomy, were included. Clinical records of these patients were reviewed for clinical features, laboratory tests, and findings on radiological imaging.

Results:

Out of 700 consecutive cholecystectomies reviewed, 34 had histologically proven XGC (4.85%). Two patients had simultaneous presence of GB carcinoma with XGC. The most common presenting symptoms were right upper quadrant pain in 32 (94%) patients, jaundice in 9 (36%) patients, and fever in 5 (14%) patients. The most common radiological finding was cholelithiasis in 85.2% of cases. Thick-walled GB was present in 79.4% of patients; irregular wall thickening was present in 20.5% of patients. Intramural nodule was present in two patients, whereas hepatic invasion was observed in 11% and pericholecystic infiltration was present in 8.8% of patients. Regional lymphadenopathy was present in 9 (26.4%) patients.

Conclusion:

Clinical presentation and laboratory parameters were unequivocal due to considerable overlap. Despite recent advances in radiology, none have significant sensitivity and specificity to accurately diagnose XGC preoperatively. Intraoperative frozen section can add to the diagnosis with limited accuracy. The diagnosis of XGC can be confirmed only on histopathological examination.

Spectrum of Xanthogranulomatous Processes in the Abdomen and Pelvis: A Pictorial Review of Infectious, Inflammatory, and Proliferative Responses

OBJECTIVE

Xanthogranulomatous (XG) processes are rare inflammatory conditions with the characteristic pathologic feature of lipid-laden macrophages or histiocyte cells. Imaging findings are nonspecific and can simulate aggressive neoplastic processes. XG processes can be caused by infection, inflammation, histolytic process, or an inherited lysosomal disorder. XG infectious processes are mainly seen in cholecystitis and pyelonephritis, but several other organs can also be involved. Histiocytic processes can be divided into Langerhans and non-Langerhans cell histiocytosis. The non-Langerhans cell histiocytosis entities include Erdheim-Chester disease, Rosai-Dorfman disease, juvenile xanthogranuloma, and hemophagocytic lymphohistiocytosis. The inherited lysosomal disorders resulting in XG processes include Nieman-Pick, Gaucher, and other lysosomal storage disorders.

CONCLUSION

Radiologists need to be able to recognize features of xanthogranulomatous processes to help facilitate patient management.

Contrast-Enhanced Ultrasound in the Assessment of Patients with Indeterminate Abdominal Findings at Positron Emission Tomography Imaging

Widespread use of fluorodeoxyglucose-positron emission tomography (PET) in cancer imaging may result in a number of indeterminate and false-positive findings. We investigated the role of contrast-enhanced ultrasound (CEUS) as a second-level option after inconclusive PET. We reviewed CEUS images acquired over 4 y, selecting the examinations performed specifically to better assess an unclear PET image. Final diagnosis was confirmed by biopsy, surgery, further imaging or follow-up. Seventy CEUS examinations were performed after a PET scan (44 PET examinations, 19 PET-computer tomography [CT] examinations and 7 PET-CECT examinations). The target organ was the liver in 54 cases, spleen in 12, gallbladder in 2 and pancreas and kidney in one each. In 6 of 70 cases, CEUS was performed because of a negative PET (no uptake) despite an abnormal finding on the CT images of the PET-CT study; CEUS allowed a correct diagnosis in all of these. In 20 of 70 cases, the PET findings were categorized as indeterminate and non-specific (non-specific fluorodeoxyglucose uptake in PET report with no standardized uptake value given); CEUS reached a correct diagnosis in 19 of the 20 cases with one false negative. In 34 of 70 cases, PET was indeterminate, but specific (fluorodeoxyglucose uptake with a standardized uptake value provided); CEUS reached a correct diagnosis in 30 of these 34 cases. In 10 of 70 cases, PET was categorized as determinate but to be investigated because of discrepancy with clinical or imaging findings; CEUS a definitive diagnosis in 9 of 10 cases. CEUS proved to be effective option in the assessment of cancer patients with indeterminate PET findings.

Xanthogranulomatous gastritis of the remnant stomach mimicking a malignant tumor: A case report

Xanthogranulomas are known to develop in the gallbladder and kidney. Xanthogranuloma of the stomach is a rare disease, and to the best of our knowledge, only a few cases have been reported to date. The present patient was a 64-year-old man who underwent a wide resection of the stomach following a Billroth-I reconstruction for a gastric ulcer ~40 years prior to the current presentation. Due to tarry stools, a gastrointestinal endoscopy was performed, leading to identification of an ulcerated gastric lesion located at the previous suture line at the lesser curvature of the remnant stomach. This lesion was elevated, appearing to indicate a submucosal tumor. Positron emission tomography revealed uptake of fluorodeoxyglucose radiotracer by the tumor. Although not indicated by the biopsy specimens, a malignant tumor of the remnant stomach was suspected, in the form of a malignant gastrointestinal tumor or remnant gastric cancer. Curative resection of the tumor was successfully performed. Histological examination of the resected specimens revealed xanthogranulomatous inflammation consisting of foamy histiocytes and plasma cells, however, no cancer cells were observed. The tumor was diagnosed as xanthogranulomatous gastritis that mimicked a malignant tumor of the remnant stomach. The present study therefore indicates that inflammatory tumors should be considered in the differential diagnosis of malignant tumors.

Xanthogranulomatous cholecystitis in the laparoscopic era is still a challenging disease

BACKGROUND

Xanthogranulomatous cholecystitis is an unusual inflammatory process of the gallbladder which is difficult to diagnose and manage and may be confused with gallbladder cancer. Many surgeons and pathologists are not familiar with this condition. We aim to highlight this condition and to review the role of laparoscopy in its management.

PATIENTS AND METHODS

We reviewed the records of 4406 patients who underwent cholecystectomy in 8 years at two teaching hospitals in North Jordan. Forty-two cases of Xanthogranulomatous cholecystitis were identified. The details of these patients were analyzed. The findings were compared with results of a previous study in all cholecystectomy patients conducted in the same centers.

RESULTS

The incidence of Xanthogranulomatous cholecystitis was 0.95 %. Twenty-five patients (59.5 %) presented as acute emergencies. Nine patients (21.4 %) had jaundice. Ultrasound showed marked gallbladder wall thickening in 36 patients (85.7 %). Compared with all cholecystectomy patients, xanthogranulomatous cholecystitis patients showed higher conversion rate from laparoscopic to open cholecystectomy (31.4 vs. 3.2 %, p < 0.001) and higher morbidity (33.3 vs. 6.4 % p < 0.001).

CONCLUSIONS

Xanthogranulomatous cholecystitis is rare. Acute presentation, associated jaundice, and gallbladder wall thickening should raise the suspicion of the condition. Laparoscopic cholecystectomy is associated with high conversion rate.

Expression of GLUT-1 and GLUT-3 in xanthogranulomatous cholecystitis induced a positive result on ¹⁸F-FDG PET: report of a case

Although several reports have revealed that fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) is useful for differentiating between benign and malignant lesions in the gallbladder, the positive results of (18)F-FDG PET are not specific for malignancy because (18)F-FDG is also accumulated in inflammatory lesions. It is known that the most important pathway for (18)F-FDG to enter the cell body is mediated by the facilitative glucose transporter-1 (GLUT-1) through GLUT-3. We herein present a case of xanthogranulomatous cholecystitis (XGC) with a positive result on (18)F-FDG PET. In this case, GLUT-1 and GLUT-3 were both positively expressed in inflammatory cells at the gallbladder wall of XGC and this is the first report to reveal GLUT expression in XGC. This report reveals that surgeons should carefully consider the appropriate treatment of gallbladder tumor, even with a positive result on (18)F-FDG PET.

An old enemy not to be forgotten during PET CT scanning of cancer patients: tuberculosis

Aim of the study

Positron emission tomography–computed tomography (PET CT) scan is commonly used in current medical oncology practice as an imaging method. In this study we present data from cancer patients who were followed at our clinic and suspected of having tuberculosis during PET CT scanning. After the biopsy, they were diagnosed with concomitant tuberculosis.

Material and methods

In this study, 14 patients who applied to our clinic and followed up due to cancer, and had PET CT scanning for the preliminary staging or further evaluation, were included. The patients were diagnosed with metastatic or recurrent disease, and their biopsy results revealed tuberculosis.

Results

The mean age was 57.8 years with SD (standard deviation) 13.1 years and gender distribution of 78.6% (n = 11) females and 21.4% (n = 3) males. None of the patients had tuberculosis in their personal history (0%). Among the patients, 5 (35.7%) were diagnosed with tuberculosis during the preliminary staging, whereas 9 (64.3%) were diagnosed during the follow-up after the treatment. The median time to tuberculosis diagnosis was 11 months (min–max: 3–24 months) after the treatment. The most commonly involved lymph nodes during PET CT scanning were mediastinal in 8 (64.3%), axillary in 3 (21.4%) and para-aortic in 3 (21.4%) patients. The mean SUV_max (maximum standardised uptake value) of lymph node involved by PET CT scanning was defined as 8.5 (SD 2.6).

Conclusions

Despite all improvements in modern medicine, tuberculosis is still a serious public health problem. It should always be considered in differential diagnosis while evaluating PET CT scanning results of cancer patients, because it may cause false positive results.

Xanthogranulomatous cholecystitis: a European and global perspective

INTRODUCTION

Xanthogranulomatous cholecystitis (XGC) is often mistaken for, and may predispose to, gallbladder carcinoma (GB Ca). This study reviews the worldwide variation of the incidence, investigations, management and outcome of patients with XGC.

METHODS

Data from 29 studies, cumulatively containing 1599 patients, were reviewed and results summarized by geographical region (Europe, India, Far East and Americas) with 95% confidence intervals (CIs) to present variability within regions. The main study outcomes were incidence, association with GB Ca and treatment of patients with XGC.

RESULTS

Overall, the incidence of XGC was 1.3-1.9%, with the exception of India where it was 8.8%. The incidence of GB Ca associated with XGC was lowest in European studies (3.3%) varying from 5.1-5.9% in the remaining regions. Confusion with or undiagnosed GB Ca led to 10.2% of patients receiving over or under treatment.

CONCLUSIONS

XGC is a global disease and is associated with GB Ca. Characteristic pathological, radiological and clinical features are shared with GB Ca and contribute to considerable treatment inaccuracy. Tissue sampling by pre-operative endoscopic ultrasound or intra-operative frozen section is required to accurately diagnose gallbladder pathology and should be performed before any extensive resection is performed.

A case of xanthogranulomatous cholecystitis suspected to be adenocarcinoma based on the intraoperative peritoneal washing cytology

INTRODUCTION

Xanthogranulomatous cholecystitis (XGC) is a variant of chronic cholecystitis. XGC remains difficult to distinguish from gallbladder cancer radiologically and macroscopically.

PRESENTATION OF CASE

A 63-year-old female was referred to our hospital because of a gallbladder tumor. Abdominal CT and MRI revealed a thickened gallbladder that had an obscure border with the transverse colon. FDG-PET showed a high uptake of FDG in the gallbladder. Therefore, under the preoperative diagnosis of an advanced gallbladder cancer with invasion to the transverse colon, a laparotomy was performed. Because adenocarcinoma was suspected based on the intraoperative peritoneal washing cytology (IPWC), cholecystectomy and partial transverse colectomy were performed instead of radial surgery. However, the case was proven to be XGC with no malignant cells after the operation.

DISCUSSION

In patients with gallbladder cancer who underwent surgery in our institute from 2000 to 2009, the prognosis after the operation of patients with only positive IPWC tended to be better than that of patients with definitive peritoneal disseminated nodules. It is true that in some cases, it is difficult to differentiate XGC from gallbladder carcinoma pre- and intra-operatively.

CONCLUSION

Surgical procedures should be selected based on the facts that there are long-term survivors with gallbladder cancer diagnosed with positive IPWC, and that some patients with XGC are initially diagnosed to have carcinoma by IPWC, as was seen in our case.

Mass-forming xanthogranulomatous cholecystitis masquerading as gallbladder cancer

BACKGROUND

Mass-forming xanthogranulomatous cholecystitis (XGC), an uncommon inflammatory pathology of gallbladder (GB), masquerades as gallbladder cancer (GBC) and diagnosis is often a histological surprise.

METHODS

A retrospective analysis of prospectively collected database of patients with GB mass operated between August 2009 and September 2012 was conducted to determine clinical, radiological, and intraoperative findings that might aid in the preoperative diagnosis of mass-forming XGC and ascertain their optimal management strategy.

RESULTS

Of the 566 patients with GB mass and suspected GBC, 239 were found to be inoperable on preoperative workup and 129 patients had unresectable disease on staging laparoscopy/laparotomy. Of the 198 with resectable disease, 31 were reported as XGC on final histopathology (Group A), while 167 were GBC (Group B). Of these 31 patients, six with an intraoperative suspicion of benign pathology underwent cholecystectomy with segments IVb and V resection, and frozen section histopathology. Twenty-five underwent radical cholecystectomy, with (n = 10) or without (n = 15) adjacent organ resection. In comparison, anorexia and weight loss were significantly more in Group B (p = 0.001 and <0.001). Intraoperatively, empyema and associated gallstones were more common in Group A (p = 0.011 and <0.001). On computed tomography (CT) of the abdomen, continuous mucosal line enhancement and intramural hypodense bands were significantly more in Group A (p < 0.001 and 0.025). While CT abdomen revealed one or more features suggestive of XGC in 64.5 % (20/31) of patients in Group A, 11(35.5 %) did not have any findings suggestive of XGC on imaging.

CONCLUSION

Mass-forming XGC mimics GBC, making preoperative and intraoperative distinction difficult. While imaging findings can help in suspecting XGC, definitive diagnosis require histopathological examination. Presence of typical radiological findings, however, can help in avoiding extended radical resection in selected cases.

Chronic cholecystitis with hilar bile duct stricture mimicking gallbladder carcinoma on positron emission tomography: A case report

Thickening of the gallbladder wall is observed in patients with gallbladder carcinoma, as well as in those with chronic cholecystitis. It is difficult to distinguish between benign and malignant gallbladder wall thickening with conventional diagnostic imaging techniques, such as abdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI), particularly in patients with bile duct strictures. Currently, the fluorine-18 2-fluorodeoxyglucose positron emission tomography/CT (F-18 FDG PET/CT) scan is widely used in the differentiation of cholecystitis from gallbladder carcinoma. However, the F-18 FDG PET/CT scan may also be responsible for false-positive diagnosis. This case report focuses on a 74-year-old male who presented with thickening of the gallbladder wall and hilar bile duct stricture, originally misdiagnosed as gallbladder carcinoma by US and MRI. F-18 FDG PET/CT also demonstrated increased activity. This case was ultimately proven to be chronic cholecystitis by postoperative pathological examination and it is presented in order to emphasize the significance of considering the possibility of false-positive diagnosis by PET/CT, as a result of inflammatory lesions. Therefore, PET/CT should not be considered the gold standard for the discrimination between benign and malignant gallbladder wall thickening.

When should we recommend use of dual time-point and delayed time-point imaging techniques in FDG PET?

FDG PET and PET/CT are now widely used in oncological imaging for tumor characterization, staging, restaging, and response evaluation. However, numerous benign etiologies may cause increased FDG uptake indistinguishable from that of malignancy. Multiple studies have shown that dual time-point imaging (DTPI) of FDG PET may be helpful in differentiating malignancy from benign processes. However, exceptions exist, and some studies have demonstrated significant overlap of FDG uptake patterns between benign and malignant lesions on delayed time-point images. In this review, we summarize our experience and opinions on the value of DTPI and delayed time-point imaging in oncology, with a review of the relevant literature. We believe that the major value of DTPI and delayed time-point imaging is the increased sensitivity due to continued clearance of background activity and continued FDG accumulation in malignant lesions, if the same diagnostic criteria (as in the initial standard single time-point imaging) are used. The specificity of DTPI and delayed time-point imaging depends on multiple factors, including the prevalence of malignancies, the patient population, and the cut-off values (either SUV or retention index) used to define a malignancy. Thus, DTPI and delayed time-point imaging would be more useful if performed for evaluation of lesions in regions with significant background activity clearance over time (such as the liver, the spleen, the mediastinum), and if used in the evaluation of the extent of tumor involvement rather than in the characterization of the nature of any specific lesion. Acute infectious and non-infectious inflammatory lesions remain as the major culprit for diminished diagnostic performance of these approaches (especially in tuberculosis-endemic regions). Tumor heterogeneity may also contribute to inconsistent performance of DTPI. The authors believe that selective use of DTPI and delayed time-point imaging will improve diagnostic accuracy and interpretation confidence in FDG PET imaging.

High b-value diffusion-weighted magnetic resonance imaging for gallbladder lesions: differentiation between benignity and malignancy

BACKGROUND

Recently, the clinical application of diffusion-weighted magnetic resonance imaging (DWI) has been expanding to abdominal organs. However, only a few studies on gallbladder diseases have been published. The aim of this study was to evaluate the usefulness and limitations of high b-value DWI for gallbladder diseases.

METHODS

A total of 153 patients (mean age 60 ± 15 years, 78 males) who had undergone DWI for evaluating gallbladder wall thickening or polypoid lesions were included in this study. Of these 153 patients, 36 had gallbladder cancer and 117 had benign gallbladder diseases (67 chronic cholecystitis, 44 adenomyomatosis, four cholesterol polyp, one gallbladder adenoma, and one xanthogranulomatous cholecystitis). We evaluated the positive signal rate with DWI and the apparent diffusion coefficient (ADC) value of each disease.

RESULTS

The positive signal rate with DWI was significantly higher in gallbladder cancer (78 %) than in benign gallbladder diseases (22 %) (p < 0.001). The mean ADC value of gallbladder cancer was (1.83 ± 0.69) × 10(-3) mm(2)/s and that of benign gallbladder diseases was (2.60 ± 0.54) × 10(-3) mm(2)/s (p < 0.001). Benign gallbladder diseases with acute cholecystitis or a history of that had a higher positive signal rate with DWI (p < 0.001) and a lower ADC value (p = 0.018) than those without such conditions.

CONCLUSION

DWI can contribute to the improvement of the diagnostic capability for gallbladder wall thickening or polypoid lesions by compensating for weaknesses of other modalities by its many advantages, although cases with acute cholecystitis or such history sometimes show false-positive on DWI.

Xanthogranulomatous cholecystitis mimicking gallbladder cancer and causing obstructive cholestasis

BACKGROUND

Xanthogranulomatous cholecystitis (XGC) is a destructive inflammatory disease of the gallbladder that can mimic gallbladder carcinoma.

METHODS

We present the case of a 35-year-old Hispanic male complaining of right upper quadrant pain and jaundice for 2 months prior to admission. He denied a history of fever, nausea/vomiting, and weight loss. The past medical history was relevant only for diabetes. He had no previous history of jaundice or previous operations.

RESULTS

CA19-9 was slightly elevated (52 U/mL). Abdominal ultrasonography showed an irregular thickening of the gallbladder wall and no gallstones were detected. CT scan also revealed an irregular thickening of the wall of the gallbladder body suggestive of malignancy. At laparotomy, the mass was adherent to the duodenum and colon, and although the frozen section biopsy was negative, the intraoperative findings were suggestive of malignancy, and the patient underwent left liver trisegmentectomy, resection of the common bile duct and Roux-en-Y hepaticojejunostomy. Pathological examination unexpectedly revealed XGC without malignancy.

CONCLUSIONS

Preoperative and intraoperative differential diagnosis of XGC from gallbladder carcinoma remains a challenge when it is associated with inflammatory involvement of surrounding tissues. Since gallbladder carcinoma and XGC may coexist, radical resection is justified when malignancy cannot be completely ruled out.

Hepatobiliary scintigraphy in acute cholecystitis

Hepatobiliary scintigraphy is a mature imaging technique for evaluation of patients with acute cholecystitis (AC). It is effective in calculous and acalculous forms of AC. The test is used in contemporary medical practice as the arbiter when the findings from screening abdominal ultrasound do not fit a clinical picture. It is also performed in severely ill patients who have AC suspected on other testing, but whose frail condition and high operative risk demand the highest level of certainty. This review, therefore, examines all technique variations of hepatobiliary scintigraphy, offering an approach that may best fit a variety of clinical situations and philosophies on AC.

Xanthogranulomatous gastritis mimicking malignant GIST on F-18 FDG PET

Xanthogranulomatous gastritis (XGG) is a rare inflammatory lesion of the stomach, with only 11 reported cases worldwide. Furthermore, reports on the use of detailed diagnostic imaging in XGG are not available. Herein, we describe a case of XGG with detailed diagnostic imaging mimicking malignant gastrointestinal stromal tumor (GIST) in light of the current literature. A 79-year-old woman who presented with epigastric pain was referred to our hospital. Upper gastrointestinal endoscopy revealed an elevated lesion similar to a submucosal tumor (SMT). F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) showed intense FDG uptake in the mass. Additional imaging studies revealed a malignant GIST, which was suspected of having infiltrated the left lobe of the liver. Open surgery was carried out, but tumorous lesions were not found. For exact histopathological diagnosis, partial resection of the thickening gastric wall was performed, and XGG was diagnosed. We conclude that benign conditions, including XGG, should be considered when intense FDG uptake in SMT is found.

Xanthogranulomatous cholecystitis: sonographic and CT features and differentiation from gallbladder carcinoma: a pictorial essay

The imaging features of xanthogranulomatous cholecystitis closely resemble those of gallbladder carcinoma, especially those of the wall-thickening variety. There is an overlap between these two conditions with respect to the clinical features and certain imaging findings. However, certain finer details like the presence of intramural hypoattenuating nodules and the type of mucosal enhancement may help to differentiate these two conditions. In this article, we have highlighted some of these imaging features. The importance of making an accurate diagnosis lies in the significant difference between the prognosis and the surgical management of the two disease entities.

A severe case of xanthogranulomatous cholecystitis along with a review of CT indications for nonoperative management including percutaneous drainage

BACKGROUND

Xanthogranulomatous cholecystitis is a rare but severe presentation of cholecystitis characterized by extensive inflammation of the gallbladder wall with characteristic histopathological features. Frequently, the inflammatory mass resembles gallbladder cancer macroscopically, which further complicates therapeutic decisions.

CASE PRESENTATION

We report a case of xathogranulomatous cholecystitis with characteristic computed tomography findings, which was managed by percutaneous drainage of the gallbladder, giving the opportunity for a delayed elective cholocystectomy with an excellent postoperative outcome.

DISCUSSION

Recent studies give emphasis on certain criteria for the differential diagnosis of xanthogranulomatous cholecystitis against carcinoma. Characteristic computed tomography features are usually sufficient to establish the diagnosis with safety and decide a nonoperative management of the disease in the acute phase. Percutaneous gallbladder drainage is regarded as a safe and an efficient method for the initial treatment of severe cases.

Case report of xanthogranulomatous cholecystitis, review of its sonographic and magnetic resonance findings, and distinction from other gallbladder pathology

A case of xanthogranulomatous cholecystitis is presented with a brief review of its sonographic and magnetic resonance features. These imaging features are also compared to those seen in gallbladder adenomyomatosis and gallbladder carcinoma. While there are many overlapping imaging findings in these entities, it is important to recognize distinguishing characteristics so a correct surgical approach is chosen. Laparoscopic cholecystectomy attempted with existing xanthogranulomatous cholecystitis has an increased surgical complication rate compared to open cholecystectomy and often necessitates intraoperative conversion to open cholecystectomy.

Multi-site abdominal tuberculosis mimics malignancy on 18F-FDG PET/CT: Report of three cases

¹⁸F-fluorodeoxyglucose positron emission/computed tomography (¹⁸F-FDG PET/CT) imaging, an established procedure for evaluation of malignancy, shows an increased ¹⁸F-FDG uptake in inflammatory conditions. We present three patients with abdominal pain and weight loss. Conventional imaging studies indicated that abdominal neoplasm and ¹⁸F-FDG PET/CT for assessment of malignancy showed multiple lesions with intense ¹⁸F-FDG uptake in abdomen of the three cases. However, the three patients were finally diagnosed with multi-site abdominal tuberculosis (TB). Of them, two were diagnosed with TB by pathology, one was diagnosed with TB clinically. They recovered after anti-TB therapy. Few reports on accumulation of ¹⁸F-FDG in abdominal TB are available in the literature. A high index of suspicion is necessary to achieve an early diagnosis and a better outcome of the disease.

Can EUS-guided FNA distinguish between gallbladder cancer and xanthogranulomatous cholecystitis?

BACKGROUND

EUS-guided FNA (EUS-FNA) is a useful modality for sampling various targets, but its applicability to gallbladder (GB) mass lesions is limited.

OBJECTIVE

To determine the usefulness of EUS-FNA for diagnosing GB mass lesions.

DESIGN

Single-center, retrospective, case-series study.

SETTING

Tertiary-care referral center.

PATIENTS

This study involved 15 consecutive patients who underwent EUS-FNA of GB mass lesions. We punctured GB masses in patients with suspected xanthogranulomatous cholecystitis to distinguish them from malignancy, and in patients with unresectable GB carcinoma for pathological confirmation. The final diagnosis was based on surgical histopathological results or follow-up outcome.

INTERVENTIONS

EUS-FNA.

MAIN OUTCOME MEASUREMENTS

Evaluation of EUS-FNA sampling adequacy rate and diagnostic yield.

RESULTS

Xanthogranulomatous cholecystitis was suspected in 6 of the 15 patients. EUS-FNA revealed foam cells (n = 3), inflammatory cells (n = 1, proven by cholecystectomy), and GB carcinoma (n = 1), and the amount of the aspirate was insufficient in one case (xanthogranulomatous cholecystitis was later proven by extended hepatectomy). The mean follow-up period of the patients with xanthogranulomatous cholecystitis was 1177 days. Adenocarcinoma was confirmed by EUS-FNA in 8 of the 9 patients with suspected unresectable GB carcinoma, and the FNA was inconclusive in one. All 10 patients with GB carcinoma underwent chemotherapy. The overall sampling adequacy was 86.6%. The accuracy of EUS-FNA for detecting malignancy and for the final diagnosis was 93.3% (95% CI, 62.4%-99.9%) and 80% (95% CI, 54%-93.7%), respectively.

LIMITATIONS

A small patient cohort and a retrospective design with potential selection bias.

CONCLUSIONS

Malignant GB mass lesions can be safely and accurately differentiated by EUS-FNA. Thus, patients with xanthogranulomatous cholecystitis can avoid undue extensive surgery.