Short cases – Gallbladder case 1 – NUS Pathweb

Gallbladder Case 1

Case writer: Dr Ooi Li Yin

Clinical history:

72M with loss of weight
CT scan showed mural gallbladder thickening.
MRI showed eccentric enhancing soft tissue thickening of the gallbladder wall, with an enlarged lymph node adjacent to the gallbladder. Malignancy was not excluded.
A radical cholecystectomy was performed. Intraoperatively, the gallbladder was adherent to the colonic mesentery.
Grossly, the fundus showed firm irregular thickening with a whitish cut surface and some softer, friable, yellowish areas. A few gallstones were present.
What are the histologic findings?
What are your differential diagnoses?
What ancillary tests would you do?

Click picture to enlarge

Gallbladder wall markedly thickened by sheets of foamy histiocytes with occasional multinucleated giant cells (inset), admixed with lymphocytes, plasma cells and neutrophils
Extensive mural fibrosis and destruction of the normal gallbladder wall architecture, with foci of ulceration and granulation tissue formation
Ruptured Rokitansky-Aschoff sinuses associated with the xanthogranulomatous changes

Xanthogranulomatous cholecystitis
Malakoplakia – sheets of histiocytes containing Michaelis-Gutmann bodies (highlighted by von Kossa or calcium stains)
Infection-related granulomatous cholecystitis – consider mycobacteria or fungi (GMS, Ziel-Neelsen, Fite stain)
IgG4-related cholecystitis – dense lymphoplasmacytic inflammation, storiform fibrosis and obliterative phlebitis; assess IgG4-positive plasma cells and the clinical context (e.g. serum IgG4 levels)
Grossly and on imaging, gallbladder adenocarcinoma due to the appearance of a mass which may be adherent to adjacent structures

Diagnosis

Learning Points

Xanthogranulomatous cholecystitis (XGC) is a benign destructive inflammatory condition characterized histologically by foamy or spindled histiocytes, acute and chronic inflammation, multinucleated giant cells and fibrosis.
Grossly, XGC typically produces a thickened gallbladder wall with firm, yellow-tan nodular areas. It may extend into the liver or pericholecystic fat and form adhesions to adjacent structures, producing a mass-like appearance that mimics carcinoma.
Gallstones are present in most cases. Leakage of bile through mucosal ulcers, fissures or ruptured Rokitansky–Aschoff sinuses triggers the xanthogranulomatous inflammatory response, which may be compounded by bacterial infection.
XGC can closely mimic—and occasionally coexist with—gallbladder carcinoma. Thorough sampling is therefore essential, particularly in areas showing a mass, irregular mucosa or focal induration. Cytokeratin may be helpful when in doubt, to exclude the presence of an invasive epithelial component.