Understanding Xanthogranulomatous Cholecystitis: A Rare Mimicker of Gallbladder Carcinoma

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Understanding Xanthogranulomatous Cholecystitis: A Rare Mimicker of Gallbladder Carcinoma

Comprensión de la colecistitis xantogranulomatosa: una rara réplica del carcinoma de vesícula biliar

담낭암의 희귀한 유사 질환인 황색육아종성 담낭염 이해

Keywords: xanthogranulomatous cholecystitis, RUQ pain CT, gallbladder wall thickening, gallbladder cancer mimic, intramural cystic spaces, fat stranding gallbladder, xanthogranulomatous inflammation, cholecystectomy findings, rare gallbladder diseases, radiology gallbladder diagnosis

Introduction

Xanthogranulomatous cholecystitis (XGC) is a rare, chronic inflammatory condition of the gallbladder that often mimics gallbladder carcinoma on imaging. This diagnostic dilemma necessitates careful radiological interpretation and often surgical confirmation. In this column, we delve into the intricacies of XGC through a compelling case of a 55-year-old male presenting with intermittent right upper quadrant (RUQ) pain. This post aims to serve both as a comprehensive review and an educational case analysis for radiologists, gastroenterologists, and medical students alike.

Case Presentation

A 55-year-old man with a known history of small bowel neuroendocrine tumor presented for a routine surveillance CT scan. He reported mild intermittent right upper quadrant (RUQ) pain over the past month.

CT Findings

(See Figure 1 below for coronal, sagittal, and axial contrast-enhanced CT images)

  • Gallbladder wall thickening up to 1.2 cm, irregular and extensive.

  • Subtle intramural cystic spaces.

  • Mild surrounding fat stranding.

  • Hepatic parenchymal hypoattenuation, suggesting inflammatory extension.

Figure 1. Contrast-enhanced CT images demonstrating gallbladder wall thickening with intramural cystic spaces and fat stranding.

Six months prior, a non-contrast CT showed a normal gallbladder without wall thickening or fat stranding.


Differential Diagnosis

The CT findings prompted a broad differential diagnosis:

  • Acute cholecystitis

  • Chronic cholecystitis

  • Xanthogranulomatous cholecystitis

  • Gallbladder carcinoma

  • Metastases

  • Hyperplastic cholecystoses

Final Diagnosis

After undergoing cholecystectomy, the pathology report confirmed:

“Xanthogranulomatous cholecystitis with hemorrhage.”

Discussion

▶ Etiology and Pathogenesis

XGC results from:

  • Recurrent or chronic obstruction of the cystic duct,

  • Rupture of Rokitansky–Aschoff sinuses, and

  • Extravasation of bile into the gallbladder wall.

This initiates a granulomatous reaction characterized by:

  • Infiltration of foamy histiocytes,

  • Giant cells, and

  • Cholesterol clefts.

▶ Epidemiology

  • Peak incidence: 5th to 6th decade.

  • Slight female predominance.

  • Incidence varies from 0.7% to 13.2% in cholecystectomy specimens globally.

▶ Clinical Presentation

Symptoms often mimic:

  • Acute cholecystitis: RUQ pain, fever, nausea.

  • Gallbladder cancer: Weight loss, palpable mass (rare).

▶ Imaging Features

 Ultrasound:

  • Hypoechoic intramural nodules.

  • Gallbladder wall thickening.

CT Scan:

  • Thickened gallbladder wall with intramural cystic areas.

  • Pericholecystic fat stranding.

  • Hepatic microabscesses adjacent to the gallbladder (mimicking liver invasion).

  • Mucosal line enhancement preserved.

  • Biliary obstruction or lymphadenopathy may be seen.

 

Figure 2. Axial CT slice showing liver hypoattenuation adjacent to the gallbladder (inflammatory extension).
 

Figure 3. Coronal image showing multiple intramural cystic spaces within thickened gallbladder wall.

▶ Pathology

Histologically, the lesion shows:

  • Lipid-laden macrophages (xanthoma cells),

  • Fibrosis and granulomatous inflammation,

  • Possible hemorrhage or necrosis.

▶ Treatment

  • Surgical cholecystectomy is the treatment of choice.

  • In many cases, malignancy cannot be excluded without surgical pathology.

▶ Prognosis

  • Benign, non-neoplastic condition.

  • Rarely associated with complications like perforation, sepsis, or biliary stricture.

  • The prognosis is excellent post-resection.

Quiz

1. What is the most salient finding on CT?

(1) Subtle intramural cystic spaces and mild fat stranding with gallbladder wall thickening
(2) Bilateral wedge-shaped renal hypoattenuation
(3) Rim-enhancing fluid collection in the right lower liver
(4) All of the above

2. What is included in the differential diagnosis?

(1) Acute cholecystitis
(2) Gallbladder carcinoma
(3) Metastasis
(4) All of the above

3. What is the most appropriate next step?

(1) Right upper quadrant ultrasound
(2) Repeat CT in 6 months
(3) Surgical resection

4. Which of the following is a risk factor for gallbladder carcinoma?

(1) Chronic inflammation
(2) Smoking
(3) High-sugar diet
(4) All of the above

5. What are CT features suggestive of XGC?

(1) Intramural cystic spaces
(2) Fat stranding
(3) Hepatic microabscesses
(4) All of the above

Answer & Explanation:

1. Answer: (1) Explanation: The gallbladder wall thickening with subtle intramural cystic spaces is the hallmark imaging finding of XGC.

2. Answer: (4) Explanation: The imaging findings are non-specific and overlap with several pathologies, necessitating a broad differential.

3. Answer: (3) Explanation: Due to the difficulty in excluding malignancy, cholecystectomy is warranted.

4. Answer: (4) Explanation: Multiple environmental and inflammatory factors contribute to gallbladder cancer risk.

5. Answer: (4) Explanation: The constellation of these findings is typical for XGC.

Conclusion

Xanthogranulomatous cholecystitis poses a significant diagnostic challenge due to its radiologic overlap with gallbladder carcinoma. Through meticulous imaging analysis and a high index of suspicion, clinicians can guide timely surgical intervention, which remains the gold standard for diagnosis and cure. Awareness of its characteristic features—such as intramural cysts, fat stranding, and preserved mucosal enhancement—can aid in distinguishing this rare but important entity.

References

[1] A. D. Levy, L. A. Murakata, R. M. Abbott, and C. A. Rohrmann Jr., “Benign tumors and tumorlike lesions of the gallbladder and extrahepatic bile ducts: Radiologic-pathologic correlation,” Radiographics, vol. 22, no. 2, pp. 387–413, 2002.

[2] L. Ratanaprasatporn, J. W. Uyeda, J. R. Wortman, I. Richardson, and A. D. Sodickson, “Multimodality imaging, including dual-energy CT, in the evaluation of gallbladder disease,” Radiographics, vol. 38, no. 1, pp. 75–89, 2018.

[3] V. P. Singh et al., “Xanthogranulomatous cholecystitis: What every radiologist should know,” World J Radiol., vol. 8, no. 2, pp. 183–191, 2016.

[4] P. Guzman-Valdivia, “Xanthogranulomatous cholecystitis: 15 years’ experience,” World J Surg.., vol. 28, no. 3, pp. 254–257, 2004.

[5] M. C. Yeh, S. K. Chang, Y. F. Lee et al., “Xanthogranulomatous cholecystitis: 10-year experience in a single medical center,” BMC Gastroenterology, vol. 10, no. 1, p. 39, 2010.

[6] S. Rajaguru et al., “Role of MRI in differentiating XGC from gallbladder cancer,” Eur Radiol., vol. 31, pp. 1932–1941, 2021.

[7] B. Kasliwal et al., “CT features of XGC and their differentiation from gallbladder carcinoma: A pictorial review,” Insights Imaging, vol. 12, pp. 1–9, 2021.

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