Diagnosis: Porcelain gallbladder
We diagnosed this patient with porcelain gallbladder based on her history, physical exam, and x-ray, which revealed a well-defined air gas bubble encased in a calcified pouch. (The patient’s lab work was unremarkable and the ultrasound revealed the same findings as seen on the x-ray.)
Porcelain gallbladder is a rare condition.1 It is characterized by intramural calcifications of the gallbladder wall, which is rarely seen with chronic cholecystitis.2
There are a few theories behind the etiology of porcelain gallbladder. One theory is that gallstones can irritate the gallbladder wall, leading to inflammation and then calcification. Others believe that porcelain gallbladder is due to the obstruction of cystic ducts, which leads to bile stasis in the gallbladder, followed by the accumulation of calcium carbonate salts.3
Patients may present with biliary pain or a firm palpable mass in the right upper quadrant. However, patients are often asymptomatic.4
Cancer risk. There is about a 2% to 3% risk of gallbladder cancer in patients with porcelain gallbladder.5 The nature of the calcification has been linked to the probability that a patient will develop gallbladder cancer. Specifically, there is a higher probability of gallbladder cancer if discontinuous calcification is noted, or if only some portion of the gallbladder wall has calcified.6 About 80% of all gallbladder cancers are adenocarcinomas.6
Differential diagnosis includes GERD, cholecystitis
Right upper quadrant pain is associated with acute hepatitis, acute cholecystitis, acute pancreatitis, gastroesophageal reflex disease (GERD), ulcers, and umbilical hernias. In this patient’s case, her history and physical examination made a number of diagnoses less likely, including acute cholecystitis, GERD, ulcers, and an umbilical hernia. In addition, normal values on the patient’s lipase and amylase tests ruled out pancreatitis.
Imaging brought things into focus. The most significant finding in this case was the abdominal x-ray, which showed a well-defined air gas bubble encased in a calcified pouch.
In addition to an x-ray or an ultrasound, a computed tomography scan can confirm the diagnosis of porcelain gallbladder.