Gallbladder Empyema Workup

Updated: Nov 30, 2021
  • Author: Benjamin Pace, MD, FACS; Chief Editor: Praveen K Roy, MD, AGAF  more...
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Laboratory Studies

Laboratory tests for presumed empyema of the gallbladder include complete blood cell (CBC) count with differential, liver function tests, prothrombin time (PT), and activated partial thromboplastin time (aPTT).

Persistent and even increasing leukocytosis at levels greater than 15,000/dL (with a left shift on differential) despite appropriate antibiotic therapy is characteristic of empyema of the gallbladder. However, this scenario may occur in association with gangrenous cholecystitis and with several other differential diagnoses.

When arising from complicated acute cholecystitis, liver chemistry findings associated with empyema of the gallbladder are usually within reference ranges, which helps differentiate this condition from empyema of the gallbladder and/or cholangitis secondary to distal biliary tract obstruction. One exception is empyema of the gallbladder in which the enlarged "penile" gallbladder compresses the common/hepatic bile ducts (Mirizzi syndrome), giving rise to mildly elevated alkaline phosphatase and bilirubin levels.

Serial blood cultures are beneficial in patients with bacteremia; positive results help direct antibiotic therapy.


Imaging Studies

Ultrasonography of the gallbladder is indicated in presumed empyema of the gallbladder. The finding of an enlarged, distended gallbladder, thickened gallbladder wall, and associated pericholecystic fluid points to an acute inflammatory process involving the gallbladder. [3] Although suggestive, this does not adequately differentiate uncomplicated acute cholecystitis from the complication with empyema and/or gangrene. Most importantly, it contraindicates further conservative management and signals the need for prompt intervention.

Although ultrasonography is the preferred examination for probable cases of empyema, the condition is frequently discovered on computed tomography (CT) scans performed with other conditions on the differential diagnosis in mind.

On diffusion-weighted (DWI) magnetic resonance imaging (MRI), diffusion restriction in non-neoplastic lesions sometimes provides additional information that can help to establish a correct diagnosis in patients for whom conventional images have yielded equivocal findings. DWI may help to differentiate gallbladder empyema from dense bile or sludge in the gallbladder. [4]



Endoscopic retrograde cholangiopancreatography (ERCP) is not indicated if empyema of the gallbladder is thought likely because it may delay definitive diagnosis and operative treatment.

Histologic findings include a pus-filled gallbladder, with or without calculi, and an acute suppuration of the gallbladder wall, with or without areas of gangrene and perforation.