Diagnostic Ultrasound - Abdomen and Pelvis

Xanthogranulomatous Cholecystitis
TERMINOLOGY
Abbreviations
• Xanthogranulomatous cholecystitis (XGC)
Synonyms
• Fibroxanthogranulomatous cholecystitis
Definitions
• Rare inflammatory process causing focal or diffuse
destruction of gallbladder (GB) wall, with accumulation of
lipid-laden macrophages, fibrous tissue, and acute and
chronic inflammatory cells
IMAGING
General Features
• Diffuse wall thickening with intramural nodules
(hypoechoic [US], hypodense [CT], slightly hyperintense
[MR]) is characteristic
• Preoperative distinction between XGC and GB carcinoma
difficult
Ultrasonographic Findings
• Gallbladder wall thickening, focal or diffuse
• Gallstones
• Intramural hypoechoic nodules or bands
• Gallbladder fossa mass, ± infiltrative, ± obscured margins
between gallbladder and liver
CT Findings
• Diffuse GB wall thickening
• Hypodense intramural nodules/bands
• Continuous linear mucosal enhancement sign
• Infiltration into adjacent organs
Imaging Recommendations
• Presence of 3 of the following has > 80% sensitivity, 100%
specificity, 91% accuracy in differentiating XGC from GB
carcinoma
○ Diffuse wall thickening
○ Intramural nodules (hypoechoic, hypodense, slightly
T2WI hyperintense)
○ Continuous mucosal line
○ Absence of hepatic invasion
○ Absence of biliary dilation
DIFFERENTIAL DIAGNOSIS
Gallbladder Carcinoma
• Many overlapping features (wall thickening/soft tissue
mass, nodularity, infiltration of surrounding tissues)
• Periportal lymphadenopathy, biliary obstruction
• More likely associated with anorexia, weight loss, and
palpable mass
Gangrenous Cholecystitis
• Asymmetric GB wall thickening
• Intraluminal membranes (sloughed mucosa or clot strands)
Hyperplastic Cholecystoses
• GB wall thickening
• Echogenic foci in Rokitansky-Aschoff (RA) sinuses, with
reverberation "comet tail" artifact
PATHOLOGY
General Features
• Etiology
○ Gallstones (96-100%)
○ Pathogenesis
– Extravasation of bile into GB wall from rupture of RA
sinuses or by mucosal ulceration → inflammatory
reaction in which macrophages and fibroblasts
phagocytose biliary lipids → xanthomatous cells →
fibrous reaction and scarring
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Typical symptoms of acute cholecystitis
– Right upper quadrant pain associated with eating,
nausea/vomiting, Murphy sign, leukocytosis
○ Obstructive jaundice
• Other signs/symptoms
○ Can present as acute pancreatitis, biliary colic
Demographics
• Age
○ Mean age at presentation: 44-63 years
• Epidemiology
○ Prevalence: 0.7% in USA patients with symptomatic
gallbladder disease
Natural History & Prognosis
• Active and destructive inflammatory process with
considerable morbidity
• Can coexist with gallbladder carcinoma
Treatment
• Surgical resection is definitive treatment
• Prognosis: Morbidity dependent on postoperative
complications
DIAGNOSTIC CHECKLIST
Consider
• Difficult to distinguish from GB carcinoma preoperatively
Image Interpretation Pearls
• Presence of intramural (hypoechoic, hypodense, slightly
T2WI hyperintense) nodules within thickened GB wall is
highly suggestive
SELECTED REFERENCES
1. Bennett G et al: Cholelithiasis, cholecystitis, choledocholithiasis, and
hyperplastic cholecystoses. In Gore RM et al: Textbook of Gastrointestinal
Radiology. 4th ed. Philadelphia: Saunders Elsevier. Ch. 77, 2015
2. Revzin MV et al: The gallbladder: uncommon gallbladder conditions and
unusual presentations of the common gallbladder pathological processes.
Abdom Imaging. Epub ahead of print, 2014
3. Smith EA et al: Cross-sectional imaging of acute and chronic gallbladder
inflammatory disease. AJR Am J Roentgenol. 192(1):188-96, 2009
4. Catalano OA et al: MR imaging of the gallbladder: a pictorial essay.
Radiographics. 28(1):135-55; quiz 324, 2008
5. Levy AD et al: Benign tumors and tumorlike lesions of the gallbladder and
extrahepatic bile ducts: Radiologic-pathologic correlation. RadioGraphics.
22: 387-413, 2002
Diagnoses: Biliary System
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