Contrast-enhanced computed tomography revealed homogeneous enhancement of the thickened GB wall with multiple intramural cystic areas Figure 2a. Mucosal enhancement was relatively well preserved, except for a focal breach in the region of the body of the GB adjacent to the liver Figure 2b ; however, fat planes between the remaining organs were maintained.
Minimal fat stranding was noted surrounding the GB fundus. No gallstones, significant periportal lymphadenopathy or intrahepatic biliary radical dilatation was observed. Magnetic resonance imaging demonstrated a few intramural T2 hyperintense nodules within the wall of GB, confirming the diagnosis of XGC Figure 3a—c. After intravenous gadolinium administration, the GB wall showed uniform enhancement with focal discontinuous mucosal enhancement. Although the adjacent liver had shown T2 hyperintense signal suggestive of oedema, post-contrast images indicated a maintained boundary between the enhanced GB wall and liver Figure 3 , suggesting inflammatory changes rather than invasion.
Histology showed polymorphs and foamy histiocytes, in keeping with XGC Figure 4. The patient subsequently underwent an open simple cholecystectomy. Fine needle aspiration cytology specimen from the fundus showing foamy macrophages arrow and polymorphs on May—Grunwald—Giemsa stain, consistent with the diagnosis of xanthogranulomatous cholecystitis.
Consent was taken from the patient to include the data in the study. Xanthogranulomatous cholecystitis is an uncommon variant of chronic cholecystitis, characterised by intramural xanthogranulomatous accumulation of lipid-laden macrophages inflammation with both acute and chronic inflammatory cells of the GB. The most important association with XGC is cholelithiasis, seen in approximately Laboratory parameters are usually normal, with no associated specific liver function test discordance.
Imaging modalities play a major role in the detection of XGC. The typical sonographic findings include diffuse, symmetrical, hyperechoic wall thickening, intramural hypoechoic nodules, associated cholelithiasis or choledocholithiasis. On dynamic contrast-enhanced MRI, areas of T2 isointensity showing early and strong delayed enhancement suggest xanthogranulomas, whereas high T2 signal lesions without enhancement suggest microabscesses.
Both XGC and adenomyomatosis demonstrate wall thickening with sonographic hypoechoic intramural nodules and gallstones. Differences in imaging features of carcinoma gallbladder and xanthogranulomatous cholecystitis. Other conditions with overlapping features, such as wall thickening and mass-forming lesions of the GB with adhesions, are collectively labelled as inflammatory pseudo tumours of the GB.
These include inflammatory myofibroblastic tumours, inflammatory tumours developing as a foreign body reaction and Immunoglobulin G4 IgG4 -related cholecystitis. The authors concluded that the conditions may co-exist, especially when IgG4-related disease involves other organs. Contrast-enhanced computed tomography is the best modality for the evaluation of GB wall thickening and a systematic approach may be beneficial in arriving at an accurate diagnosis, as follows:.
Is the thickening focal or diffuse? Pathologies with diffuse thickening may or may not be associated with cholelithiasis. Gallstones are associated with acute or chronic cholecystitis, GB cancer, XGC and adenomyomatosis, while calculi are usually absent in actinomycosis, IgG4-related disease, acalculous cholecystitis and GB wall thickening secondary to hepatitis, liver cirrhosis, congestive heart failure, renal failure, pancreatitis or Dengue fever. Is the diffuse thickening symmetrical or asymmetrical?
Asymmetrical thickening is more common in malignancies as compared to inflammatory conditions. The presence of intramural nodules: intramural nodules may be seen in XGC, as well as in adenomyomatosis. However, ultrasound would distinguish between the two by the presence of comet-tail artefacts. Mucosal enhancement pattern: Kim et al. It places a tube through the skin directly into the gallbladder using ultrasound or CT guidance.
Blocked or infected bile is removed to reduce inflammation. This procedure is typically done in patients who are too sick to have their gallbladder removed. You will be sedated for this procedure. The tube typically has to stay in for at least a few weeks.
Endoscopic retrograde cholangiopancreatography ERCP : This procedure is typically done by a doctor who specializes in abdominal disorders a gastroenterologist. A camera on a flexible tube is passed from the mouth through the stomach and into the beginning of the small bowel.
This is where the common bile duct meets the small intestine. The valve mechanism called the sphincter at the end of the bile duct can be examined and opened to clear blocked bile and stones, if necessary. Doctors can also insert a small tube into the main bile duct and inject contrast material to better see the duct.
They also may use a laser fiber to destroy small gallstones or use a basket or balloon to retrieve stones or stone fragments. All of this may be done without making any incisions in the abdomen. This procedure poses a small, but real risk of pancreas inflammation or injury.
Percutaneous transhepatic cholangiography PTC : This procedure is done by a radiologist. A needle is placed in the bile ducts within the liver using imaging guidance. Contrast material is injected to help locate gallstones that may be blocking bile flow. Some stones can be removed during a PTC. Others may be bypassed by leaving a small stent in place to allow bile to get around the area of blockage.
This helps reduce inflammation. See the Biliary Interventions page for more information. Attempts have been made to differentiate benign and malignant wall thickening on the basis of classification of wall thickening into 4 patterns, as described by Jung et al [ 36 ] on heavily T2 weighted images half—Fourier acquisition single short turbo spin echo.
Type 1 shows a thin hypointense inner layer and a thick hyperintense outer layer which corresponds to the pathological diagnosis of chronic cholecystitis. Type 2 consists of two layers of ill-defined margins, suggestive of acute cholecystitis. Type 3 shows multiple hyperintense cystic spaces in the wall, correlating with the pathological diagnosis of ADM. While type 4 shows diffuse nodular thickening without layering, seen mostly in malignant cases. Several studies have reported the usefulness of diffusion-weighted images DWI for the differentiation of malignant and benign GB wall thickening.
Kitazume et al [ 37 ] suggested an apparent diffusion coefficient ADC value of less than 1. When this cutoff value was combined with morphological patterns such as massive thickening, disrupted mucosal line, and absence of a two-layered pattern, sensitivity, and specificity of Solak et al [ 38 ] reported that ADC value below 0. A mean ADC value of 1.
Fluorodeoxyglucose-positron emission tomography-CT FDG-PET has better sensitivity and specificity for distinguishing between benign and malignant tumors as compared to other diagnostic modalities[ 40 , 41 ]. FDG uptake in GB can be due to both inflammatory and malignant conditions. The thickness of the GB wall and standardized uptake value SUV max has a complementary role in addition to visual analysis for the differentiation of benign and malignant lesions. Benign conditions show less SUV max value than malignant lesions.
Diagnostic accuracy of Using a cut off value of mean GB wall thickening 8. In addition to differentiating between benign and malignant conditions, PET-CT helps in the staging of malignant lesions. A preoperative diagnosis is required to avoid unnecessary cholecystectomies in asymptomatic patients with ADM. Diffuse ADM shows symmetrical mural thickening, intramural cystic spaces, and echogenic foci causing twinkling artefacts on USG.
The comet-tail artefact was earlier considered to be specific to ADM. This artefact is caused by the accumulation of cholesterol crystals in the Rokitansky-Aschoff sinuses and can also be seen in the other benign conditions of GB. Studies have shown comet tail artefact to be a reliable sign of benignity of the lesion[ 47 ]. The pearl necklace sign, defined as linear hyperintense foci on T2-weighted images, has been described as a specific sign, especially for diffuse ADM Figure 7 [ 48 ].
However, T2 hyperintense foci can also be seen in well-differentiated mucin-producing GBC. The size, shape, number, and arrangement of the cystic components may help in the differential diagnosis. The cystic component in ADM is smaller, rounded, arranged in a linear fashion, and the wall shows a flat contour with a regular surface[ 49 ]. Well-differentiated GBC shows larger, multilobulated cystic components and the wall shows an irregular surface contour.
The mucosal and serosal layers of the GB wall surrounding the lesions are enhanced and can be observed as two hyperechoic lines in the arterial phase. The smaller non-enhancing spaces are more clearly seen during the venous phase[ 50 ]. However, if small cystic spaces are seen within the thickened GB wall, ADM is the likely diagnosis[ 53 ].
Cotton ball sign i. Morikawa et al [ 57 ] performed a retrospective study in patients who underwent surgical resection of GB with Rokitansky-Aschoff sinuses. Intramural hypoechoic nodules with a continuous mucosal line are characteristic sonographic features of XGC[ 58 ].
There is an emerging role of chemical shift imaging for the diagnosis of XGC in cases where hypoattenuating nodules are obscured. Features such as diffuse GB wall thickening, intact mucosa, intramural hypoattenuating nodules, absence of hepatic invasion, and intrahepatic dilatation favor the diagnosis of XGC Figure 8 [ 66 - 68 ].
However, preoperative diagnosis may be challenging and the diagnosis of XGC can be made confidently only on histopathology[ 69 ]. Regional lymphadenopathy has been associated with approximately Sureka et al [ 71 ] reported a discontinuous mucosal line in Few case reports of XGC have shown irregularly thickened walls with infiltration into adjacent organs[ 72 ].
A combination of gross examination of the mucosa and intraoperative frozen section examination, especially in areas of high suspicion of cancer, can accurately differentiate XGC and GBC and can also detect the simultaneous presence of both entities[ 73 ].
This may prevent extended resections in cases of XGC. Generally, arterial enhancement of the thick inner layer that shows isoattenuation to hepatic parenchyma during the venous phase; or enhancing thick inner layer in both phases, is seen in GBC. Cases of chronic cholecystitis show an isoattenuating thin inner layer during both the phases [74]. On dynamic contrast-enhanced MRI, chronic cholecystitis shows early smooth enhancement, whereas GBC shows early irregular enhancement.
The outer margin of early enhancement in GBC correlates with the extent of the tumor[ 75 ]. Diffuse GB thickening and gallstones are also seen in chronic cholecystitis, however, due to associated mural fibrosis, the GB is usually contracted and pericholecystic fluid is generally absent[ 7 , 76 ].
As previously described, XGC is associated with cholelithiasis, GB wall thickening focal or diffuse , and the presence of intramural hypoechoic nodules with continuous mucosal line[ 7 , 58 ]. Tuberculosis, lymphoma, neuroendocrine tumor, and metastasis represent rare causes of GB involvement[ 78 - 81 ].
The features of these lesions are tabulated in Table 5. Despite the advances in imaging, an accurate diagnosis of GB wall thickening may be challenging at times, and tissue sampling may be required. USG guided fine needle aspiration cytology is a quick, reliable, and cost-effective method, which can be done as an outdoor procedure.
USG allows real-time monitoring of the needle tip, and accurate and safe sampling can be done. However, sensitivity is reduced when malignancy is associated with XGC[ 86 ]. Percutaneous biopsy is required for cases that appear unresectable on imaging to look for genetic aberrations, such as ERBB2 amplification, mutations or amplification of the P13 kinase family genes, FGFR mutations or fusion, and aberrations of the chromatin modulating genes[ 87 ].
This allows the use of targeted therapy. Interventional radiologist plays an adjunctive role in preoperative management of cholangitis and postoperative biliary leaks by placing percutaneous drains under USG, CT, or fluoroscopic guidance[ 88 ]. Percutaneous drainage of the biliary system and biliary stenting are widely used methods for palliative care in GBC[ 89 ].
Percutaneous cholecystostomy is an interventional technique that is primarily employed in biliary emergencies like acute severe cholecystitis and cholangitis. Other indications include a second-line approach to access biliary tract for decompression when intra-hepatic radicles are not accessible, to dilate a benign stricture, or stent a malignant stricture[ 90 ].
Portal vein embolization is an effective method to facilitate hypertrophy of the residual liver when contemplating extended liver resections. Various minimally invasive locoregional therapies such as transarterial embolization and percutaneous ablation are under investigation for the treatment of liver metastasis in GBC cases. The commonly used embolization agents are drug-eluting beads and Yttrium[ 92 ].
Another evolving option is the implantation of hepatic artery infusion pumps, which enable continuous infusion of cytotoxic agents directly into the metastatic lesion[ 93 ]. Celiac plexus block is another palliative care therapy offered by interventional radiologists for pain control in advanced cases.
The various analgesics agents used are lidocaine, steroids, ethanol, or phenol. Studies have reported improved quality of life and decreased dependence on opioids using this method[ 94 ].
It is important to recognize the patterns of GB wall thickening, diffuse or focal, as the conditions associated with these patterns are different. Ancillary findings further help in the characterization of the cause.
The diffuse pattern of wall thickening can be seen in conditions intrinsic as well as extrinsic to the GB. If a mesh-like diffuse wall thickening is seen in a patient with known systemic disease or adjacent inflammatory reaction, the thickening can be attributed to these extrinsic causes.
Dirty shadowing within the thickened GB wall in patients with other features of acute cholecystitis should raise the suspicion for emphysematous cholecystitis, and a CT is warranted in such cases. The absence of cholelithiasis in a critically ill patient with other features of acute calculous cholecystitis is suggestive of acute acalculous cholecystitis. A multimodality imaging approach may be helpful in such conditions.
The focal pattern of GB wall thickening has a narrow differential diagnosis and is seen in conditions intrinsic to GB. An algorithmic approach for the diffuse and focal wall thickening has been outlined in respective flow charts Figure 9 - In order to increase the objectivity as well as the diagnostic accuracy of imaging findings, it is important to adopt a standardized reporting format that takes into account the key characteristics of the GB, adjacent liver, and distant sites Figure The radiologist must be aware of the different causes of GB wall thickening.
A correct diagnosis is usually established using a combination of multimodality imaging findings, clinical presentation, and laboratory parameters. An understanding of the diagnostic pitfalls in the early stages of GBC and its differentiation from benign conditions is essential for appropriate management. Advanced Search. This Article. Academic Rules and Norms of This Article. Citation of this article. Imaging-based algorithmic approach to gallbladder wall thickening. Corresponding Author of This Article.
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