xanthogranulomatous cholecystitis

Xanthogranulomatous cholecystitis (XGC) is an uncommon inflammatory disease of the gallbladder that may be difficult to differentiate from malignancy, both on imaging and pathologically. It is characterized by the presence of multiple intramural nodules.

Epidemiology

It is seen predominantly in female patients at 60-80 years of age.

Clinical presentation

Patients typically present with symptoms and signs similar to cholecystitis including right upper quadrant pain, vomiting, obstructive jaundice, cholangitis, with a positive Murphy sign and a palpable mass. Leukocytosis is generally present .

Pathology

The macroscopic appearance is of a poorly defined, nodular yellow mass that infiltrates the wall of the gallbladder. There is gallbladder wall thickening, and the process may infiltrate directly into the adjacent soft tissues, liver, duodenum, or colon .

Histologically, it consists of a mixture of ceroid (wax-like) xanthogranuloma with foamy histiocytes, multinucleated foreign body giant cells, lymphocytes, and fibroblasts containing areas of necrosis.

It is postulated that xanthogranulomatous cholecystitis results from rupture of occluded Rokitansky-Aschoff sinuses, with subsequent intramural extravasation of inspissated bile and mucin .  This further attracts histiocytes to phagocytize insoluble cholesterol.

The spectrum of pathological findings includes :

  • thickened gallbladder wall: ~90% diffuse and ~10% focal
  • infiltration of pericholecystic fat: in 45% focal, in 54% diffuse
  • hepatic extension: ~45 %
  • biliary obstruction: ~36%
  • lymphadenopathy: ~36 %
Associations

Radiographic features

Ultrasound
  • gallbladder wall thickening may be diffuse or focal
  • intramural hypoechoic nodules or bands
  • if the inflammatory process has infiltrated the adjacent liver, there may be loss of the intervening fat plane, with focal hypoechogenicity of hepatic parenchyma
  • gallstones often present
CT
  • 5-20 mm small intramural hypoattenuating nodules
  • poor/heterogeneous contrast enhancement
  • features of local infiltration, or other complications, such as perforation, abscess formation or formation of fistulous tracts

Treatment and prognosis

Because of its imaging similarity to gallbladder carcinoma, cholecystectomy is often performed. Fine needle aspiration has been performed to differentiate the two entities.

Differential diagnosis

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