Porcelain Gallbladder

Published on 19/07/2015 by admin

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Last modified 22/04/2025

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 Echogenic curvilinear structure in GB fossa with dense acoustic shadowing

– Clean posterior acoustic shadowing (no echogenic foci or “dirty” shadowing to suggest emphysema)
– Wall-echo-shadow complex not seen (unlike stones)
image Biconvex curvilinear calcification of GB wall with visualization of posterior wall of GB

– Posterior GB wall not visualized with stones or emphysematous cholecystitis
image Coarse foci of calcification in GB wall with acoustic shadowing
• CT

image Calcifications in GB wall can be thin or thick and irregular

– May involve entire wall or just a segment
image CT is most sensitive modality for identifying calcification

TOP DIFFERENTIAL DIAGNOSES

• Large gallstone or gallstones filling GB
• Emphysematous cholecystitis
• Iatrogenic high-density material in GB

CLINICAL ISSUES

• Most common in elderly female patients who are usually asymptomatic
• Traditionally thought to be associated with high risk of cancer, but recent studies suggest much weaker association (as low as 6%)
• Risk of GB cancer may depend on pattern of calcification, although evidence for this is limited

image Diffuse intramural calcification: Likely no risk of cancer
image Flecks of calcium in GB mucosa: ↑ risk of cancer
• Decision to operate depends on patient age, symptoms, morphology of calcification (diffuse vs. selective), and patient functional status
image
(Left) Transverse transabdominal ultrasound shows a curvilinear echogenic structure image in the gallbladder (GB) fossa with acoustic shadowing image, characteristic of a porcelain GB.

image
(Right) Ultrasound shows increased echogenicity throughout the GB wall image and a mass image within the fundus. The posterior GB wall is visible, unlike a GB filled with stones or emphysematous cholecystitis. Chronic cholecystitis, intramural calcification, and GB adenocarcinoma were identified at pathology.
image
(Left) Axial CECT shows partial calcification of the GB wall image. Note the subtle soft tissue density image within the GB and the blurred margin with the adjacent liver.

image
(Right) Axial CECT in the same patient demonstrates a discrete mass image in the GB invading the liver, a classic appearance for GB cancer. GB cancer is thought to be more likely with interrupted, partial GB wall calcification than with diffuse calcification.

TERMINOLOGY

Synonyms

• Calcified gallbladder (GB), calcifying cholecystitis

Definitions

• Calcification of GB wall

IMAGING

General Features

• Best diagnostic clue

image Curvilinear rim of calcification in right upper quadrant (RUQ) conforming to shape of GB
• Morphology

image 2 patterns

– Selective mucosal calcification: ↑ risk of malignancy
– Diffuse intramural calcification: ↓ risk of malignancy

Radiographic Findings

• Radiography

image Curvilinear or granular calcification in GB wall
image May involve entire wall or just a segment

Fluoroscopic Findings

• Usually nonfunctional GB on oral cholecystograms

CT Findings

• Calcification in GB wall can be thin or thick and irregular

image May involve entire wall or just a segment
• CT is most sensitive modality for identifying calcification

Ultrasonographic Findings

• Several different possible appearances

image Echogenic curvilinear structure in GB fossa with dense acoustic shadowing

– Clean posterior acoustic shadowing (no echogenic foci or “dirty” shadowing to suggest GB emphysema)
– Wall-echo-shadow complex is not seen (unlike stones filling GB)
image Biconvex curvilinear calcification of GB wall with visualization of posterior wall of GB

– Posterior GB wall not visualized in GB filled with stones or emphysematous cholecystitis
image Coarse foci of calcification in GB wall with acoustic shadowing

Imaging Recommendations

• Best imaging tool

image CT

DIFFERENTIAL DIAGNOSIS

Large Gallstone or Gallstones Filling GB

• Can be very difficult to distinguish from porcelain GB on US
• Wall-echo-shadow complex characteristic of stones
• Visualization of posterior GB wall suggests porcelain GB (rather than stones)

Emphysematous Cholecystitis

• Echogenic crescent in GB fossa with “dirty” acoustic shadowing and ring-down artifact (from gas) on ultrasound can mimic GB wall calcification
• CT can best distinguish gas from calcium

Iatrogenic High-Density Material in GB

• Iodized oil in GB wall following hepatic chemoembolization
• Vicarious excretion of high-density contrast into GB following intravenous contrast administration

PATHOLOGY

General Features

• Etiology

image Uncertain pathogenesis, but several theories

– Intermittent obstruction of GB → supersaturation of bile → accumulation of calcium carbonate → precipitation in wall
– Intramural hemorrhage from chronic cholecystitis → mural calcification
– Dystrophic mural calcification related to chronic inflammation of GB wall due to gallstones
• Associated abnormalities

image Gallstones or milk of calcium bile (95% of cases)
image GB carcinoma (association weaker than previously thought)

– Uniform thin calcification of wall without soft tissue mass probably not significant risk factor

Gross Pathologic & Surgical Features

• Brittle gallbladder wall with bluish discoloration
• Fibrotic wall and brittle consistency may make laparoscopic cholecystectomy technically challenging

Microscopic Features

• 2 histopathologic forms

image Coarse plaques of calcium in muscularis of GB wall
image Punctate foci of mucosal calcification

CLINICAL ISSUES

Presentation

• Most common signs/symptoms

image Almost always asymptomatic
image Symptoms (RUQ pain or palpable mass) with development of malignancy or gallstones

Demographics

• Age

image Peak occurrence in 6th decade; mean = 54 years
• Gender

image M:F = 1:5
• Epidemiology

image Rare: 0.06-0.08% of autopsies; 0.15% of cholecystectomy specimens

Natural History & Prognosis

• Incidence of cancer in porcelain GB usually quoted as 12-62% based on retrospective data from 1950s-60s; however, more recent reviews suggest weaker association
• Recent systematic review of literature with meta-analysis suggests risk of malignancy may be as low as 6%
• Risk of GB cancer may depend on pattern of calcification, although evidence for this is limited

image Diffuse intramural calcification: Likely no risk of cancer
image Flecks of calcium in GB mucosa: Significant risk of cancer

Treatment

• Decision to operate depends on patient age, symptoms, and morphology of calcification (diffuse vs. selective)
• Prophylactic cholecystectomy

image Open approach often advocated, but laparoscopic resection possible, particularly given low risk of GB carcinoma

DIAGNOSTIC CHECKLIST

Consider

• Look for GB mass on CT if porcelain GB identified

Image Interpretation Pearls

• Wall-echo-shadow sign on ultrasound can differentiate gallstones from porcelain GB
image
Coronal CECT demonstrates thick, irregular calcification image of the wall of the GB fundus. Note the subtle soft tissue density image in the GB fundus adjacent to the calfication. While the association is weaker than previously thought, such a finding should raise strong suspicion for coexistent malignancy.

image
Axial CECT demonstrates extensive calcification image of the GB wall. No malignancy was identified at cholecystectomy.
image
Transverse ultrasound demonstrates dense calcification image of the anterior GB wall, in keeping with a porcelain GB. Note the lack of a “wall-echo-shadow” complex (unlike stones) and the clean posterior acoustic shadowing image (unlike the dirty shadowing of emphysematous cholecystitis).
image
Ultrasound of a 63-year-old woman with right upper quadrant pain shows curvilinear shadowing echogenicity image within the GB wall. Marked shadowing image makes it impossible to assess the GB lumen. (Courtesy K.T. Wong, MBChB.)
image
Anteroposterior abdominal radiograph shows curvilinear eggshell-type calcification image in the right upper quadrant, which is the typical appearance for a calcified GB wall.
image
Axial NECT shows a thin, calcified wall of the GB image. The liver is nodular as a result of cirrhosis. Patients with cirrhosis have an increased prevalence of gallstones but uncommonly develop porcelain GB.
image
Axial CECT shows typical appearance of a porcelain GB. Diffuse, smooth calcification image of the GB wall is seen without associated mass or enhancement.
image
Anteroposterior radiograph shows a thin rim of calcification image in the right upper quadrant conforming to the shape of the GB.
image
Coronal CECT shows a rim of interrupted calcifications image in the lateral aspect of the GB wall.
image
NECT shows a rind of calcification in the GB wall image and dependent calcified stones image. The association between porcelain GB and carcinoma is weaker than suggested in early surgical series, but cholecystectomy may still be indicated depending on patient demographics and the type of wall calcification.
image
Axial CECT shows curvilinear calcification in the GB wall image and a heterogeneous low-attenuation mass image invading the adjacent liver representing GB carcinoma. The relationship between porcelain GB and GB cancer is controversial, but probably not as strong as previously thought.

SELECTED REFERENCES

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Brown, KM, et al. Porcelain gallbladder and risk of gallbladder cancer. Arch Surg. 2011; 146(10):1148.

Khan, ZS, et al. Reassessing the need for prophylactic surgery in patients with porcelain gallbladder: case series and systematic review of the literature. Arch Surg. 2011; 146(10):1143–1147.

Ash-Miles, J, et al. More than just stones: a pictorial review of common and less common gallbladder pathologies. Curr Probl Diagn Radiol. 2008; 37(5):189–202.

Liang, HP, et al. Porcelain gallbladder. J Am Geriatr Soc. 2008; 56(5):960–961.

Cunningham, SC, et al. Porcelain gallbladder and cancer: ethnicity explains a discrepant literature? Am J Med. 2007; 120(4):e17–e18.

Gore, RM, et al. Imaging benign and malignant disease of the gallbladder. Radiol Clin North Am. 2002; 40(6):1307–1323. [vi].

Opatrny, L. Porcelain gallbladder. CMAJ. 2002; 166(7):933.

Stephen, AE, et al. Carcinoma in the porcelain gallbladder: a relationship revisited. Surgery. 2001; 129(6):699–703.

Towfigh, S, et al. Porcelain gallbladder is not associated with gallbladder carcinoma. Am Surg. 2001; 67(1):7–10.

Rybicki, FJ. The WES sign. Radiology. 2000; 214(3):881–882.