Diagnosis
Xanthogranulomatous cholecystitis (XGC)
Findings
In October 2000, an emergent abdominal CT scan showed mild
nonspecific intrahepatic ductal dilatation. Retrospectively, an
eccentric gallbladder mass was evident at this time, but the mass
mimicked contrast within the hepatic flexure of the colon (Figure
1). When the patient was re-evaluated in January 2001 due to
worsening symptoms, abdominal sonography was interpreted initially
as normal, but repeat abdominal CT revealed a complex cystic mass
within the gallbladder fundus as well as mild intrahepatic and
extrahepatic dilatation (Figure 2). After a surgical diagnosis was
made, review of the earlier ultrasound determined that what was
originally thought to be debris within the adjacent stomach was
actually an atypically appearing fundal gallbladder mass (Figure
3).
PATHOLOGIC FINDINGS
Gross pathologic examination showed a large, chronically
inflamed gallbladder measuring 5 * 4 cm and cholelithiasis (Figure
4). Histologic analysis found xanthogranulomatous cholecystitis and
malacoplakia, with focal microscopic sinus formation (Figure
5).
Discussion
Christensen and Ishak
1 first coined the pathologic
diagnosis of XGC, describing seven patients with pseudotumors of
the gallbladder. Many pseudonyms such as ceroid granulomas,
ceroid-like histiocytosis, and fibroxanthogranulomatous
inflammation existed before the Armed Forces Institute of Pathology
formally characterized XGC.
2 The reported incidence of
XGC varies from 0.66% to 1.8%.
2-5 Preoperative diagnosis
is rarely made. Frequently, the patients are misdiagnosed as having
cholelithiasis or a primary cancer. Xanthogranulomatous
cholecystitis was initially thought to be a malignant disease
process; many studies now show that this disease behaves in a
similar fashion to another benign disorder, xanthogranulomatous
pyleonephritis (XGP).
6,7
Both of these disease processes are associated with chronic
infection and calculi that induce histiocytes to begin the
inflammatory cascade.6-8 Sjodahl9 first
speculated that gallbladder calculi creating mechanical trauma
along the mucosa incite the inflammatory response. The inflammation
causes lechitin in the bile to react with free fatty acids,
producing lysolecithin. This results in further damage to the
gallbladder mucosa, initiating a destructive
cascade.3,10 This inflammatory process progresses from
cholecystitis to XGC when the Rokitansky-Aschoff sinuses become
occluded and inspissated with bile and mucin.3,4,8,10,11
When the wall tension of the distended gallbladder exceeds its
natural compliance, the Rokitansky-Aschoff sinuses rupture,
spreading inflammation to the adjacent tissues.2-4,10
The degradation of bile results in phagocytosis of insoluble
cholesterol and bile salts by histiocytes, giving the
characteristic XGC appearance of macrophage-laden and foamy
histiocytes.2,10
Xanthogranulomatous cholecystitis has many similarities to its
original counterpart, but it is generally more severe. Similar
pathogens found in both XGC and cholecystitis include
Klebsiella, E. coli, Proteus mirabilis,
Enterobacter, and Citrobacter.12 Since
XGC is usually not suspected preoperatively, neither are its
sequelae. Complications such as gallbladder perforation, hepatic
abscess, biliary ductal stricture and obstruction, ascending
cholangitis, and biliary fistula are associated more commonly with
XGC.2-5 Although imaging modalities13,14 such
as CT, ultrasound, endoscopic retrograde cholangiopancreatography,
and percutaneous transhepatic cholangiography aid in diagnosing the
complications of XGC, only histologic examination of a surgical
specimen will accurately give the diagnosis.5 In
addition, there is an increased association of underlying carcinoma
in patients with XGC than in those with ordinary
cholecystitis.15-17
Due to the high prevalence of primary fistulas, cholecystectomy
is accompanied by excision of all surrounding xanthogranulomatous
tissue to assure removal of any fistula.2-5 Since
dissection in Calot's triangle is difficult due to the dense
fibrosis, laparoscopic surgery is rarely successful.2,8
Some have advocated subtotal cholecystectomy with drainage of the
subhepatic space to decrease the likelihood of iatrogenic
injury.17 Also, due to the high incidence of associated
fistulas and malignancies, many advocate intraoperative
cholangiography.5
CONCLUSION
Xanthogranulomatous cholecystitis is an uncommon variant of
cholecystitis that is rarely diagnosed preoperatively. It is
generally more virulant than ordinary cholecystitis, but the same
pathogens are isolated from both, implicating a primarily
histiocytic driven inflammatory mechanism as the cause of
complicating sequelae.
1. Christensen AH, Ishak KG. Benign tumors and pseudotumors of the
gallbladder.
Arch Pathol. 1970;90:423-432.
2. Reed A, Ryan C, Schwartz S. Xanthogranulomatous
cholecystitis. J Am Col Surg. 1994;179:249-252.
3. Dao AH, Wong SW, Adkins RB. Xanthogranulomatous
cholecystitis: A clinical and pathologic study of twelve cases.
Amer Surg. 1989;55:2-5.
4. McCoy JJ, Vila R, Petrossian G, et al. Xanthogranulomatous
cholecystitis; Report of two cases. J SC Med Assoc.
1976;72:78-79.
5. Houston JP, Collins MC, Reed MW, et al. Xanthogranulomatous
cholecystitis. Br J Surg. 1994;81:1030-1032.
6. Povysil C, Konickova L. Experimental xanthogranulomatous
pyelonephritis. Invest Urol. 1972;9:313-318.
7. Malek RS, Elder JS. Xanthogranulomatous pyelonephritis: A
critical analysis of 26 cases and of the literature. J
Urol. 1978;119:589-592.
8. Howard TJ, Bennion RS, Thompson JE. Xanthogranulomatous
cholecystitis: A chronic inflammatory pseudotumor of the
gallbladder. Am Surg. 1991;57:821-824.
9. Sjodahl R, Tagesson C, Wetterfors J. On the pathogenesis of
acute cholecystitis. Surg Gynecol Obstet.
1978;146:199-202.
10. Goodman ZD, Ishak KG. Xanthogranulomatous cholecystitis.
Am J Surg Pathol. 1981;5:653-659.
11. Reyes CV, Jablokow VR, Reid R. Xanthogranulomatous
cholecystitis: Report of seven cases. Am Surg.
1981;47:322-325.
12. Martin LF, Zinner SH, Kagan JP, et al. Bacteriology of the
human gallbladder in cholelithiasis and cholecystitis. Am
Surg. 1983;49:151-154.
13. Parna JA, Acinas O, Bueno J, et al. Xanthogranulomatous
cholecystitis: Clinical, sonographic, and CT findings in 26
patients. AJR Am J Roentgenol. 2000;174:979-983.
14. Kim PN, Ha HK, Kim YH, Lee MG. Ultrasound finding of
xanthogranulomatous cholecystitis. Clin Radiol.
1998;53:290-292.
15. Duber C, Storkel S, Wagner PK, Muller J. Xanthogranulomatous
cholecystitis mimicking carcinoma of the gallbladder: CT findings.
J Comput Assist Tomogr. 1984;8:1195-1198.
16. Benbow EW, Taylor PM. Simultaneous xanthogranulomatous
cholecystitis and primary adenocarcinoma of the gallbladder.
Histopathology. 1988;12:672- 675.
17. Yoshida J, Chijiiwa K, Shimura H, et al. Xanthogranulomatous
cholecystitis versus gallbladder cancer: Clinical differentiating
factors. Am Surg. 1997;63:367-371.
18. Borman PC, Terblanche J. Subtotal cholecystectoy: For the
difficult gallbladder in portal hypertension and cholecystitis.
Surgery. 1985;98:1-6.