A Case of Porcelain Gallbladder Showing High Levels of CA19-9.

Porcelain gallbladder is a rare condition characterized by an extensive calcification of the gallbladder wall. It is associated with an increased risk of gallbladder cancer and elevated levels of tumor marker CA19-9, which is typically seen in pancreatic and biliary cancers. We present a case of a 60-year-old woman who presented with upper abdominal pain and nausea. Imaging revealed both a porcelain gallbladder and common bile duct stones. Initially, the patient underwent endoscopic retrograde cholangiopancreatography (ERCP) for the removal of the common bile duct stones. Notably, following the removal of the stones, the patient's CA19-9 levels were significantly elevated, reaching 6076 U/mL. Subsequently, she underwent a laparoscopic cholecystectomy. Histopathological examination and immunostaining for CA19-9 were performed on the resected specimen. Histopathology revealed marked fibrosis, calcification, and xanthogranulomatous inflammation of the gallbladder wall without evidence of malignancy. Immunostaining showed strong CA19-9 positivity in the inflamed gallbladder mucosal epithelium. Postoperatively, the patient's CA19-9 levels returned to normal (17 U/mL). This case highlights that a benign porcelain gallbladder can present with abnormally high CA19-9 levels, potentially mimicking malignancy. Reports of CA19-9 elevation in porcelain gallbladder are limited, and in most cases, significant CA19-9 elevation has been associated with malignancy. This case also demonstrates that benign conditions such as biliary obstruction, chronic inflammation, and xanthogranulomatous cholecystitis can cause significant elevations in CA19-9 levels. Therefore, careful differentiation and comprehensive evaluation are crucial for accurate diagnosis and appropriate management in such cases.